Phase change inks

ABSTRACT

Disclosed is a phase change ink composition including an ink carrier and a colorant, said ink being suitable for use in an indirect printing process wherein the ink is jetted from a printhead onto a heated intermediate transfer member and subsequently transferred from the intermediate transfer member to a final recording substrate, wherein: (a) the ink exhibits the characteristic of being jetted from the printhead onto the intermediate transfer member when the ink at a temperature of about 125° C. or lower; (b) the ink exhibits the characteristic of being jetted without purging from a printer maintained at a standby temperature of about 100° C. or lower; and (c) the ink has a cohesive failure temperature of at least about 56° C.

CROSS-REFERENCE TO RELATED APPLICATIONS

Copending Application U.S. Ser. No. 11/126,745, filed May 11, 2005, entitled “Method of Purification of Polyalkylene Materials,” filed May 11, 2005, with the named inventors San-Ming Yang, Thomas E. Enright, Val Magdalinis, Ahmed Alzamly, Man C. Tam, Carol A. Jennings, Peter M. Kazmaier, and Marko D. Saban, the disclosure of which is totally incorporated herein by reference, discloses a method of purifying polyalkylene. Also included are microencapsulated Gyricon beads, phase change ink, and toners comprising the purified polyalkylene.

Copending Application U.S. Ser. No. 11/290,221, filed concurrently herewith, entitled “Phase Change Inks,” with the named inventors Bo Wu, Stephan V. Drappel, Trevor J. Snyder, Donald R. Titterington, Jule W. Thomas, Jr., C. Geoffrey Allen, Harold R. Frame, and Wolfgang G. Wedler, the disclosure of which is totally incorporated herein by reference, discloses a phase change ink comprising (a) a colorant and (b) a phase change ink carrier, said carrier comprising (i) a branched triamide and (ii) a polyethylene wax having an average peak molecular weight of from about 350 to about 730, a polydispersity of from about 1.03 to about 3.0, and an asymmetrical molecular weight distribution skewed toward the high molecular weight end. Also disclosed is a process which comprises (1) incorporating into an ink jet printing apparatus a phase change ink comprising (a) a colorant and (b) a phase change ink carrier, said carrier comprising (i) a branched triamide and (ii) a polyethylene wax having an average peak molecular weight of from about 350 to about 730, a polydispersity of from about 1.03 to about 3.0, and an asymmetrical molecular weight distribution skewed toward the high molecular weight end; (2) melting the ink; and (3) causing droplets of the melted ink to be ejected in an imagewise pattern onto a substrate.

Copending Application U.S. Ser. No. 11/291,055, filed concurrently herewith, entitled “Phase Change Inks,” with the named inventors Bo Wu, Trevor J. Snyder, Stephan V. Drappel, Jule W. Thomas, Jr., Donald R. Titterington, and C. Geoffrey Allen, the disclosure of which is totally incorporated herein by reference, discloses a phase change ink comprising (a) a colorant and (b) a phase change ink carrier, said carrier comprising (i) a branched triamide and (ii) a polyethylene wax having an average peak molecular weight of from about 350 to about 730 and a polydispersity of from about 1.05 to about 3.0. Also disclosed is a process which comprises (1) incorporating into an ink jet printing apparatus a phase change ink comprising (a) a colorant and (b) a phase change ink carrier, said carrier comprising (i) a branched triamide and (ii) a polyethylene wax having an average peak molecular weight of from about 350 to about 730 and a polydispersity of from about 1.05 to about 3.0; (2) melting the ink; and (3) causing droplets of the melted ink to be ejected in an imagewise pattern onto a substrate.

Copending Application U.S. Ser. No. 11/290,263, filed concurrently herewith, entitled “Phase Change Inks,” with the named inventors Bo Wu, Trevor J. Snyder, Jule W. Thomas, Jr., and Patricia Ann Wang, the disclosure of which is totally incorporated herein by reference, discloses a phase change ink comprising (a) a colorant and (b) a phase change ink carrier, said carrier comprising (i) a branched triamide and (ii) a polyethylene wax having an average peak molecular weight of from about 350 to about 730 and a polydispersity of from about 1.0001 to about 1.500. Also disclosed is a process which comprises (1) incorporating into an ink jet printing apparatus a phase change ink comprising (a) a colorant and (b) a phase change ink carrier, said carrier comprising (i) a branched triamide and (ii) a polyethylene wax having an average peak molecular weight of from about 350 to about 730 and a polydispersity of from about 1.0001 to about 1.500; (2) melting the ink; and (3) causing droplets of the melted ink to be ejected in an imagewise pattern onto a substrate.

Copending Application U.S. Ser. No. 11/291,056, filed concurrently herewith, entitled “Colorant Compounds,” with the named inventors Jeffery H. Banning, Bo Wu, and C. Wayne Jaeger, the disclosure of which is totally incorporated herein by reference, discloses colorant compounds of the formulae

and wherein R₁, R₂, R₃, M, A, E, G, J, m, n, and p are as defined therein.

Copending Application U.S. Ser. No. 11/291,057, filed concurrently herewith, entitled “Phase Change Inks,” with the named inventors Jeffery H. Banning, Bo Wu, and C. Wayne Jaeger, the disclosure of which is totally incorporated herein by reference, discloses a phase change ink composition comprising a phase change ink carrier and a colorant compound of the formula

or mixtures thereof, wherein R₁, R₂, R₃, M, A, E, G, J, m, n, and p are as defined therein.

Copending Application U.S. Ser. No. 11/290,258, filed concurrently herewith, entitled “Phase Change Inks Containing Specific Colorants,” with the named inventors Bo Wu, Trevor J. Snyder, Jeffery H. Banning, and Jule W. Thomas, Jr., the disclosure of which is totally incorporated herein by reference, discloses a phase change ink composition comprising (a) a phase change ink carrier comprising (1) an amide; and (2) a polyethylene wax having an average peak molecular weight of from about 350 to about 730 and a polydispersity of from about 1.0001 to about 1.5; and (b) a colorant compound of the formula

or mixtures thereof, wherein R₁, R₂, R₃, M, A, E, G, J, m, n, and p are as defined therein.

Copending Application U.S. Ser. No. 11/290,222, filed concurrently herewith, entitled “Phase Change Inks Containing Fischer-Tropsch Waxes,” with the named inventors Bo Wu, Patricia Ann Wang, Trevor J. Snyder, and Jule W. Thomas, Jr., the disclosure of which is totally incorporated herein by reference, discloses a phase change ink comprising (a) a colorant and (b) a phase change ink carrier, said carrier comprising (i) an amide and (ii) a Fischer-Tropsch wax having an average peak molecular weight of from about 300 to about 800 and a polydispersity of from about 1.001 to about 3. Also disclosed is a process which comprises (1) incorporating into an ink jet printing apparatus a phase change ink comprising (a) a colorant and (b) a phase change ink carrier, said carrier comprising (i) an amide and (ii) a Fischer-Tropsch wax having an average peak molecular weight of from about 300 to about 800 and a polydispersity of from about 1.001 to about 3; (2) melting the ink; and (3) causing droplets of the melted ink to be ejected in an imagewise pattern onto a substrate.

BACKGROUND

Disclosed herein are hot melt or phase change inks and methods for the use thereof. More specifically, disclosed herein are hot melt or phase change inks particularly suitable for use in phase change ink jet printing processes with reduced energy requirements. One embodiment is directed to a phase change ink composition comprising an ink carrier and a colorant, said ink being suitable for use in an indirect printing process wherein the ink is jetted from a printhead onto a heated intermediate transfer member and subsequently transferred from the intermediate transfer member to a final recording substrate, wherein: (a) the ink can be jetted from the printhead onto the intermediate transfer member when the ink is maintained at a temperature of about 125° C. or lower; (b) the ink can be jetted without purging from a printer maintained at a standby temperature of about 100° C. or lower; and (c) the ink has a cohesive failure temperature of at least about 56° C.

In general, phase change inks (sometimes referred to as “hot melt inks”) are in the solid phase at ambient temperature, but exist in the liquid phase at the elevated operating temperature of an ink jet printing device. At the jet operating temperature, droplets of liquid ink are ejected from the printing device and, when the ink droplets contact the surface of the recording substrate, either directly or via an intermediate heated transfer belt or drum, they quickly solidify to form a predetermined pattern of solidified ink drops. Phase change inks have also been used in other printing technologies, such as gravure printing, as disclosed in, for example, U.S. Pat. No. 5,496,879 and German Patent Publications DE 4205636AL and DE 4205713AL, the disclosures of each of which are totally incorporated herein by reference.

Phase change inks for color printing typically comprise a phase change ink carrier composition which is combined with a phase change ink compatible colorant. In a specific embodiment, a series of colored phase change inks can be formed by combining ink carrier compositions with compatible subtractive primary colorants. The subtractive primary colored phase change inks can comprise four component dyes, namely, cyan, magenta, yellow and black, although the inks are not limited to these four colors. These subtractive primary colored inks can be formed by using a single dye or a mixture of dyes. For example, magenta can be obtained by using a mixture of Solvent Red Dyes or a composite black can be obtained by mixing several dyes. U.S. Pat. No. 4,889,560, U.S. Pat. No. 4,889,761, and U.S. Pat. No. 5,372,852, the disclosures of each of which are totally incorporated herein by reference, teach that the subtractive primary colorants employed can comprise dyes from the classes of Color Index (C.I.) Solvent Dyes, Disperse Dyes, modified Acid and Direct Dyes, and Basic Dyes. U.S. Pat. No. 5,621,022, the disclosure of which is totally incorporated herein by reference, discloses the use of a specific class of polymeric dyes in phase change ink compositions.

Phase change inks have also been used for applications such as postal marking, industrial marking, and labelling.

Phase change inks are desirable for ink jet printers because they remain in a solid phase at room temperature during shipping, long term storage, and the like. In addition, the problems associated with nozzle clogging as a result of ink evaporation with liquid ink jet inks are largely eliminated, thereby improving the reliability of the ink jet printing. Further, in phase change ink jet printers wherein the ink droplets are applied directly onto the final recording substrate (for example, paper, transparency material, and the like), the droplets solidify immediately upon contact with the substrate, so that migration of ink along the printing medium is prevented and dot quality is improved.

Compositions suitable for use as phase change ink carrier compositions are known. Some representative examples of references disclosing such materials include U.S. Pat. No. 3,653,932, U.S. Pat. No. 4,390,369, U.S. Pat. No. 4,484,948, U.S. Pat. No. 4,684,956, U.S. Pat. No. 4,851,045, U.S. Pat. No. 4,889,560, U.S. Pat. No. 5,006,170, U.S. Pat. No. 5,151,120, U.S. Pat. No. 5,372,852, U.S. Pat. No. 5,496,879, European Patent Publication 0187352, European Patent Publication 0206286, German Patent Publication DE 4205636AL, German Patent Publication DE 4205713AL, and PCT Patent Application WO 94/04619, the disclosures of each of which are totally incorporated herein by reference. Suitable carrier materials can include paraffins, microcrystalline waxes, polyethylene waxes, ester waxes, fatty acids and other waxy materials, fatty amide containing materials, sulfonamide materials, resinous materials made from different natural sources (tall oil rosins and rosin esters, for example), and many synthetic resins, oligomers, polymers, and copolymers.

U.S. Pat. No. 6,860,930 (Wu et al.), the disclosure of which is totally incorporated herein by reference, discloses a phase change ink composition comprising (a) a colorant and (b) a carrier comprising a polyamide, wherein the polyamide component of the carrier contains at least about 10 percent by weight of a branched triamide.

U.S. Patent Publication 2005/0130054 (Yuan et al.), the disclosure of which is totally incorporated herein by reference, discloses wax based inks for phase change/hot melt inkjet printing or thermal transfer printing applications. Also disclosed are waxes useful for toners for use in electrostatographic printing applications. Both materials are prepared using a wax having a narrow melting range. The narrow melting range of the wax reduces energy requirements in printing applications. The use of the waxes also promotes release for high speed printing and especially promotes fast drying in wax based ink applications.

U.S. Pat. No. 6,001,904 (Matzinger et al.), the disclosure of which is totally incorporated herein by reference, discloses phase change (hot melt) ink compositions for use in a phase change (hot melt) ink jet recording device in which recording is conducted by thermally melting the ink at a temperature above ambient temperature (20° C.) to provide prints that possess high quality images, scratch resistance, abrasion resistance, low-temperature storage stability and flexibility, offset and pick resistance, adhesion, and other desired properties to comprise: (a) from about 0.1% to about 30% of one or more colorants; and (b) from about 0.1 to about 99.9% of one or more reversibly-crosslinked-polymers. Components other than those listed above may be included in the ink compositions to achieve specific printer, substrate, or end use requirements. Furthermore, the invention also includes methods for the preparation of reversibly-crosslinked-polymers and for their use in the above-described inks.

U.S. Pat. No. 6,923,853 (Kremers et al.), the disclosure of which is totally incorporated herein by reference, discloses a meltable ink which is solid at room temperature, which ink is suitable for use in an indirect printing process, in which printing process the ink is transferred, by the use of an inkjet printhead, to a transfer element, whereafter the ink is transferred to a receiving material under pressure from the transfer element, the ink having a composition such that it is pressure-transferable at a temperature between a bottom temperature limit and a top temperature limit, wherein the ink has a deformation energy of less than 20×10⁵ Pa·s at a temperature equal to said top temperature limit.

While known compositions and processes are suitable for their intended purposes, a need remains for improved phase change ink compositions. In addition, a need remains for phase change inks that can be jetted at temperatures below about 125° C. Further, a need remains for phase change inks that can be jetted with reduced energy requirements. Additionally, a need remains for phase change inks that can be jetted with less expensive printheads. There is also a need for phase change inks that enable improved thermal stability of the inks manifested as the color's stability over time when heated in printers. In addition, there is a need for phase change inks that enable improved printer reliability. Further, there is a need for phase change inks that enable quick recovery times from standby mode. Additionally, there is a need for phase change inks that enable printing with “instant-on” mode. A need also remains for phase change inks that exhibit desirable viscosity values at reduced printing temperatures. In addition, a need remains for phase change inks that enable the aforementioned advantages and also exhibit good printing characteristics, such as transfixing properties (including dither and solid fill dropout performance), acceptable jetting reliability, folding and creasing performance, color intensity, recovery after standby mode, and the like. Further, a need remains for phase change inks that generate images with improved hardness. Additionally, a need remains for phase change inks that generate images with improved gloss. There is also a need for phase change inks that exhibit reduced sweating; sweating is a problem wherein some ink ingredients migrate to the surface of solid ink sticks and aggregate at the ink stick surface inside the printer; the sticky “sweat” gradually drains down to the bottom and can cause the ink sticks to be difficult to slide in the ink load racks in the printers. In addition, there is a need for phase change inks that generate images with reduced showthrough when printed on paper substrates. Further, there is a need for phase change inks that exhibit reduced clogging of printheads while exhibiting all of the aforementioned advantages. Additionally, there is a need for phase change inks that enable reduced standby temperatures of phase change ink jet printheads without leading to clogging of the printhead or the need for a purge upon recovery to the operational jetting temperature. A need also remains for phase change inks with desirably low freezing points. In addition, a need remains for phase change inks that transfer efficiently from an intermediate transfer member to a final recording substrate when the intermediate transfer member is at a desirably high temperature to enable efficient transfer member cooling, which allows for efficient heat transfer and avoids automatic printer shutoff or slowdown from overheating of the intermediate transfer member by the ink, while also enabling jetting of the ink at a desirably low temperature. Further, a need remains for phase change inks that exhibit desirably high smudge temperatures when still-hot prints pass along guidance tracks in the printer, thereby reducing accumulation of ink along these guidance tracks that could later be transferred to blank paper.

SUMMARY

Disclosed herein is a phase change ink composition comprising an ink carrier and a colorant, said ink being suitable for use in an indirect printing process wherein the ink is jetted from a printhead onto a heated intermediate transfer member and subsequently transferred from the intermediate transfer member to a final recording substrate, wherein: (a) the ink can be jetted from the printhead onto the intermediate transfer member when the ink is maintained at a temperature of about 125° C. or lower; (b) the ink can be jetted without purging from a printer maintained at a standby temperature of about 100° C. or lower; and (c) the ink has a cohesive failure temperature of at least about 56° C.

BRIEF DESCRIPTION OF THE DRAWING

The FIGURE is a reproduction of high temperature gel permeation chromatography curves obtained for polyethylene waxes and Fischer-Tropsch waxes of different average peak molecular weight values, showing the relative amounts of molecules with different molecular weights present in the sample on the “y” axis and the retention time on the “x” axis.

DETAILED DESCRIPTION

The ink compositions disclosed herein are suitable for jetting in phase change ink jet printers. Phase change ink jet printing can be performed by direct and indirect printing processes. One embodiment as disclosed herein is directed to a process which comprises incorporating an ink as disclosed herein into an ink jet printing apparatus, melting the ink, and causing droplets of the melted ink to be ejected in an imagewise pattern onto a recording substrate. A direct printing process is also disclosed in, for example, U.S. Pat. No. 5,195,430, the disclosure of which is totally incorporated herein by reference. In a direct printing process, the ink is jetted directly onto a final recording substrate, such as paper, transparency material, or the like. In a specific embodiment, the ink compositions disclosed herein are particularly well suited for printing in an offset printing transfer or indirect printing mode, as described in, for example, U.S. Pat. Nos. 5,389,958 and 5,372,852, the disclosures of each of which are totally incorporated herein by reference. Another embodiment disclosed herein is directed to a process which comprises incorporating an ink as disclosed herein into an ink jet printing apparatus, melting the ink, causing droplets of the melted ink to be ejected in an imagewise pattern onto an intermediate transfer member, and transferring the ink in the imagewise pattern from the intermediate transfer member to a final recording substrate. In a specific embodiment, the intermediate transfer member is heated to a temperature above that of the final recording sheet and below that of the melted ink in the printing apparatus. In another specific embodiment, the intermediate transfer member and the final recording substrate are both heated; in this embodiment, variations are possible such as the intermediate transfer member being heated to a temperature above that of the final recording substrate, the intermediate transfer member being heated to a temperature below that of the final recording substrate, and the intermediate transfer member being heated to a temperature substantially equal to that of the final recording substrate. In one specific embodiment, the printing apparatus employs a piezoelectric printing process wherein droplets of the ink are caused to be ejected in imagewise pattern by oscillations of piezoelectric vibrating elements. Inks as disclosed herein can also be employed in other hot melt printing processes, such as hot melt acoustic ink jet printing, hot melt thermal ink jet printing, hot melt continuous stream or deflection ink jet printing, and the like. Phase change inks as disclosed herein can also be used in printing processes other than hot melt or phase change ink jet printing processes.

Any suitable substrate or recording sheet can be employed, including plain papers such as XEROX® 4024 papers, XEROX® Image Series papers, Courtland 4024 DP paper, ruled notebook paper, bond paper, silica coated papers such as Sharp Company silica coated paper, JuJo paper, HAMMERMILL LASERPRINT® paper, and the like, transparency materials, fabrics, textile products, plastics, polymeric films, inorganic substrates such as metals and wood, and the like.

The ink compositions disclosed herein can be jetted in phase change ink jet printers at desirably low jetting temperatures. This characteristic enables reduced energy consumption by the ink jet printer, cost savings, improved color stability as a result of the ink being subjected to reduced temperatures over time, improved reliability of the printer as a result of the printer being operated at lower temperatures, and quick recovery times of the printer from standby mode.

The inks disclosed herein can be jetted at jetting temperatures of in one embodiment about 125° C. or lower, in another embodiment about 120° C. or lower, in yet another embodiment about 115° C. or lower, and in still another embodiment about 113° C. or lower, although the jetting temperature can be outside of these ranges.

By “jetted at jetting temperatures of about 125° C. or lower” is meant that when the ink is in the printer during standard operating mode (as opposed to during warm-up mode), the ink can be jetted with no more than about 2 percent failed jets. In specific embodiments the ink can be jetted with no more than about 1 percent failed jets, in another embodiment with no more than about 0.5 percent failed jets, and in yet another embodiment no more than about 0.25 percent failed jets. For purposes herein, the test fixture used to determine whether an ink passed or failed this test is a XEROX® PHASER® 8400 phase change ink jet printer operated with drop mass and voltage set in the as-shipped conditions for the ink designated by the manufacturer for that printer. The temperature of the ink being jetted from this printer can be modified by modifying either the hardware or the software of this machine by one of ordinary skill in the art. The print used to quantify percent failed jets includes one-half to one inch full width areas of solid fill and dithered fills (25%, 50% and 75%) for each color. Percent failed jets is the number of failed jets per total jets averaged over 10 printed pages.

Many solid ink jet printers heat the intermediate transfer member, the ink, and the final recording sheet to ensure proper transfer of the image onto the final recording sheet. An intermediate transfer member heater typically heats the intermediate transfer member and a separate printhead heater heats the printhead in which the ink is contained. These heaters consume more power at higher temperatures, and power consumption is highest at the operating temperatures. Lowering the power to the heaters allows the various components to cool off during periods of inactivity, but that in turn increases the restart time for the system as the inks and the intermediate transfer member both need to resume their operating temperatures. In addition, at a specific temperature—typically close to the temperature at which the ink will solidify—the printhead may need to be purged to ensure that all of the jets are refilled and ready to print without any negative effects on image quality.

Environmentally sensitive and marketplace regulations now call for office equipment, such as reproduction machines and multi-function devices, to be more energy efficient. Such environmental regulations or requirements for office products are covered in the United States under what is currently called the “Energy Star Program”, and under various other similar programs in Europe and elsewhere. Such similar programs include “New Blue Angel” (Germany), “Energy Conservation Law” (Japan), “Nordic Swan” (North Europe), and “Swiss Energy Efficiency Label” (Switzerland). These environmental programs as well as the market (manufacturer/customer) set forth reduced power consumption level requirements and requisite times to enter these modes. These reduced power consumption modes, such as standby, low power, power saver, energy saver, sleep, and the like, vary in power levels and consume less power than in “Ready” mode, but greater than when in “Off” mode. When the machine is in a reduced power consumption mode as required to meet these environmental program and/or market requirements, recovery times are increased. Timely and satisfactory recovery from these significantly reduced power consumption levels back to the operating temperatures are important to a customer, but can be difficult.

The ink compositions disclosed herein can be printed in phase change ink jet printers with desirably low standby temperatures. Standby temperature is the temperature at which the printer maintains the ink while in an “energy saver” mode, and by definition is able to return to the higher operational temperature without requiring a purge. The ink can be maintained at lower temperatures if desired to save energy costs, but purging of the printhead would then be required to clear the jets of solidified ink. This characteristic is desirable for reasons similar to those for which low jetting temperatures are desirable. Low standby temperatures reduce power consumption and reduce ink cooking. They can also potentially increase reliability and decrease drop mass drift.

The inks disclosed herein can be maintained at standby temperatures of in one embodiment about 100° C. or lower, in another embodiment about 95° C. or lower, and in yet another embodiment about 90° C. or lower, although the standby temperature can be outside of these ranges.

By “jetted without purging from a printer maintained at a standby temperature of about 100° C. or lower” is meant that the ink can be maintained in a printer at this temperature for a period of at least about 1 week and subsequently jetted at its operational jetting temperature without any need for purging and with no more than about 2 percent failed jets. In specific embodiments the ink can be jetted with no more than about 1 percent failed jets, in another embodiment with no more than about 0.5 percent failed jets, and in yet another embodiment no more than about 0.25 percent failed jets. For purposes herein, the test fixture used to determine whether an ink passed or failed this test is a XEROX® PHASER® 8400 phase change ink jet printer operated with drop mass and voltage set in the as-shipped conditions for the ink designated by the manufacturer for that printer. The standby temperature of the ink being jetted from this printer can be modified by modifying either the hardware or the software of this machine by one of ordinary skill in the art. The print used to quantify percent failed jets includes one-half to one inch full width areas of solid fill and dithered fills (25%, 50% and 75%) for each color. Percent failed jets is the number of failed jets per total jets averaged over 10 printed pages. The prints are made immediately after recovery from standby and without purging the printhead.

When employed in indirect printing processes wherein the ink is jetted onto a heated intermediate transfer member, the ink compositions disclosed herein can be jetted onto and transferred off intermediate transfer members maintained at desirably high temperatures. This characteristic can be desirable because increased intermediate transfer member temperature facilitates the needed temperature gradient relative to ambient in order to transfer sufficient heat such that sustained printing can be achieved. More specifically, heat travels only from a hot body to a colder body, and the amount of heat transfer is approximately proportional to the temperature delta between the two. Therefore, heat transfers faster if the temperature difference is larger. Faster print speeds put more ink on the intermediate transfer member and thus require more intermediate transfer member cooling. Accordingly, if the temperature difference between the intermediate transfer member and ambient temperature is not sufficiently large, the intermediate transfer member will not cool fast enough to maintain its operational temperature. Higher intermediate transfer member temperatures, therefore, are desirable to enable more rapid cooling of the member by exposure to ambient temperature.

When inks are jetted onto intermediate transfer members maintained at temperatures beyond their cohesive failure temperatures, the inks do not transfer properly from the intermediate transfer member to the final recording substrate because the inner cohesive bonds within the ink become weaker than the adhesive bond between the ink and the intermediate transfer member. The ink splits apart on the intermediate transfer member, resulting in only some of the ink transferring to the final recording substrate while the remainder is left behind on the intermediate transfer member. Accordingly, while higher intermediate transfer member temperatures are desirable, heating of the intermediate transfer member cannot be to a temperature higher than the cohesive failure temperature of the ink. Typically, the intermediate transfer member can be heated to a temperature at or slightly below the cohesive failure temperature of the phase change ink, in one specific embodiment from about 4 to about 10° C. below the cohesive failure temperature of the ink.

The inks disclosed herein have cohesive failure temperatures of in one embodiment at least about 56° C., in another embodiment at least about 60° C., and in yet another embodiment at least about 65° C., although the cohesive failure temperature can be outside of these ranges.

By “cohesive failure temperature of at least about 56° C.” is meant that the ink can be maintained at about this temperature when residing on the intermediate transfer member, followed by transferring the ink to a final substrate, wherein the ink is transferred entirely to the final substrate, as opposed to the ink splitting and some of the ink remaining on the intermediate transfer member. For purposes herein, the test-fixture used to determine whether an ink passed or failed this test is a XEROX® PHASER® 8400 phase change ink jet printer operated with drop mass and voltage set in the as-shipped conditions for the ink designated by the manufacturer for that printer and the temperature of the final recording substrate set in the as-shipped conditions. The intermediate transfer member temperature of this printer can be modified by modifying either the hardware or the software by one of ordinary skill in the art. The print used to quantify cohesive failure temperature includes one inch to two inch full width areas of solid fill for each color. At every tested drum temperature, one image is printed followed by a blank sheet. To pass the cohesive failure test, the blank sheet contains no visible ink (other than the possibility of some isolated fragments near the edges of a solid fill that would be attributable to satellites from jetting). The cohesive failure temperature is the first temperature to display visible fractured ink on the blank page.

The ink compositions disclosed herein in one embodiment have peak melting points of no lower than about 50° C., in another embodiment of no lower than about 60° C., and in yet another embodiment of no lower than about 70° C., and have peak melting points in one embodiment of no higher than about 160° C., in another embodiment of no higher than about 140° C., and in yet another embodiment of no higher than about 100° C., although the peak melting point can be outside of these ranges.

The ink compositions disclosed herein in one embodiment have onset melting points of no lower than about 50° C., in another embodiment of no lower than about 52° C., and in yet another embodiment of no lower than about 55° C., and have onset melting points in one embodiment of no higher than about 75° C., in another embodiment of no higher than about 72° C., and in yet another embodiment of no higher than about 69° C., although the onset melting point can be outside of these ranges.

The ink compositions disclosed herein generally have melt viscosities at the jetting temperature (in one embodiment no lower than about 75° C., in another embodiment no lower than about 85° C., and in yet another embodiment no lower than about 95° C., and in one embodiment no higher than about 150° C., and in another embodiment no higher than about 120° C., although the jetting temperature can be outside of these ranges) in one embodiment of no more than about 30 centipoise, in another embodiment of no more than about 20 centipoise, and in yet another embodiment of no more than about 15 centipoise, and in one embodiment of no less than about 2 centipoise, in another embodiment of no less than about 5 centipoise, and in yet another embodiment of no less than about 7 centipoise, although the melt viscosity can be outside of these ranges. In another specific embodiment, the inks have viscosities of from about 7 to about 15 centipoise at temperatures of about 110, 115, and/or 120° C.

Ink compositions as disclosed herein can be of any desired or effective ingredients that enable the ink to meet the specified characteristics. For example, one embodiment of an ink that exhibits the specified characteristics comprises (a) a colorant and (b) a phase change ink carrier, said carrier comprising (i) a branched triamide and (ii) a polyethylene wax. Another embodiment of an ink that exhibits the specified characteristics comprises (a) a colorant and (b) a phase change ink carrier, said carrier comprising (i) a branched triamide and (ii) a Fischer-Tropsch wax.

Branched triamides are disclosed in, for example, U.S. Pat. No. 6,860,930, the disclosure of which is totally incorporated herein by reference. By “branched triamide” is meant that the structure of the triamide can be drawn so that each amide group is bonded to an atom or group of atoms contained in a branch other than that of the others, and that each amide group is in a different branch. By “each amide group is in a different branch”is meant that the triamide is not linear; by “linear” is meant a molecule wherein all three amide groups can be drawn as being in the same molecular chain or branch, such as linear triamides of the formulae

or the like. For purposes of the present invention, linear triamides include those wherein a line can be drawn through the three amide groups, even if one would ordinarily draw a different line. For example, a compound of the formula

is considered a linear compound for purposes of the present invention, because it can also be drawn as follows:

and accordingly would not be considered to be a branched triamide for the purposes of the inks discloses herein. For purposes of the inks disclosed herein, “branched triamines”, “branched triacids”, “branched monoamino diacids”, and “branched diamino monoacids” have similar definitions in that each of the three functional groups named can be drawn as being in a different branch from the other two.

Examples of suitable branched triamides include (but are not limited to) those generated from branched triamines, said branched triamides being of the formula

wherein R₁ is (i) an alkylene group (including linear, branched, saturated, unsaturated, cyclic, acyclic, substituted, and unsubstituted alkylene groups, and wherein hetero atoms, such as oxygen, nitrogen, sulfur, silicon, phosphorus, boron, and the like either may or may not be present in the alkylene group), in one embodiment with at least about 3 carbon atoms, in another embodiment with at least about 4 carbon atoms, in yet another embodiment with at least about 5 carbon atoms, in another embodiment with at least about 15 carbon atoms, and in yet another embodiment with at least about 21 carbon atoms, and in one embodiment with no more than about 200 carbon atoms, in another embodiment with no more than about 150 carbon atoms, and in yet another embodiment with no more than about 100 carbon atoms, although the number of carbon atoms can be outside of these ranges, (ii) an arylene group (including unsubstituted and substituted arylene groups, and wherein hetero atoms, such as oxygen, nitrogen, sulfur, silicon, phosphorus, boron, and the like either may or may not be present in the arylene group), in one embodiment with at least about 6 carbon atoms, in another embodiment with at least about 10 carbon atoms, and in yet another embodiment with at least about 14 carbon atoms, and in one embodiment with no more than about 200 carbon atoms, in another embodiment with no more than about 150 carbon atoms, and in yet another embodiment with no more than about 100 carbon atoms, although the number of carbon atoms can be outside of these ranges, (iii) an arylalkylene group (including unsubstituted and substituted arylalkylene groups, wherein the alkyl portion of the arylalkylene group can be linear, branched, saturated, unsaturated, cyclic, and/or acyclic, and wherein hetero atoms, such as oxygen, nitrogen, sulfur, silicon, phosphorus, boron, and the like either may or may not be present in either or both of the alkyl portion and the aryl portion of the arylalkylene group), in one embodiment with at least about 7 carbon atoms, in another embodiment with at least about 8 carbon atoms, and in yet another embodiment with at least about 9 carbon atoms, and in one embodiment with no more than about 200 carbon atoms, in another embodiment with no more than about 150 carbon atoms, and in yet another embodiment with no more than about 100 carbon atoms, although the number of carbon atoms can be outside of these ranges, such as benzylene or the like, or (iv) an alkylarylene group (including unsubstituted and substituted alkylarylene groups, wherein the alkyl portion of the alkylarylene group can be linear, branched, saturated, unsaturated, cyclic, and/or acyclic, and wherein hetero atoms, such as oxygen, nitrogen, sulfur, silicon, phosphorus, boron, and the like either may or may not be present in either or both of the alkyl portion and the aryl portion of the alkylarylene group), in one embodiment with at least about 7 carbon atoms, in another embodiment with at least about 8 carbon atoms, and in yet another embodiment with at least about 9 carbon atoms, and in one embodiment with no more than about 200 carbon atoms, in another embodiment with no more than about 150 carbon atoms, and in yet another embodiment with no more than about 100 carbon atoms, although the number of carbon atoms can be outside of these ranges, such as tolylene or the like, R_(a), R_(b), and R_(c) each, independently of the others, is (i) a hydrogen atom, (ii) an alkyl group (including linear, branched, saturated, unsaturated, cyclic, acyclic, substituted, and unsubstituted alkyl groups, and wherein hetero atoms, such as oxygen, nitrogen, sulfur, silicon, phosphorus, boron, and the like either may or may not be present in the alkyl group), in one embodiment with at least 1 carbon atom, in another embodiment with at least about 2 carbon atoms, in yet another embodiment with at least about 6 carbon atoms, in another embodiment with at least about 7 carbon atoms, and in yet another embodiment with at least about 10 carbon atoms, and in one embodiment with no more than about 200 carbon atoms, in another embodiment with no more than about 150 carbon atoms, and in yet another embodiment with no more than about 100 carbon atoms, although the number of carbon atoms can be outside of these ranges, (iii) an aryl group (including unsubstituted and substituted aryl groups, and wherein hetero atoms, such as oxygen, nitrogen, sulfur, silicon, phosphorus, boron, and the like either may or may not be present in the aryl group), in one embodiment with at least about 6 carbon atoms, in another embodiment with at least about 10 carbon atoms, and in yet another embodiment with at least about 14 carbon atoms, and in one embodiment with no more than about 200 carbon atoms, in another embodiment with no more than about 150 carbon atoms, and in yet another embodiment with no more than about 100 carbon atoms, although the number of carbon atoms can be outside of these ranges, (iv) an arylalkyl group (including unsubstituted and substituted arylalkyl groups, wherein the alkyl portion of the arylalkyl group can be linear, branched, saturated, unsaturated, cyclic, and/or acyclic, and wherein hetero atoms, such as oxygen, nitrogen, sulfur, silicon, phosphorus, boron, and the like either may or may not be present in either or both of the alkyl portion and the aryl portion of the arylalkyl group), in one embodiment with at least about 6 carbon atoms, in another embodiment with at least about 7 carbon atoms, and in yet another embodiment with at least about 8 carbon atoms, and in one embodiment with no more than about 200 carbon atoms, in another embodiment with no more than about 150 carbon atoms, and in yet another embodiment with no more than about 100 carbon atoms, although the number of carbon atoms can be outside of these ranges, such as benzyl or the like, or (v) an alkylaryl group (including unsubstituted and substituted alkylaryl groups, wherein the alkyl portion of the alkylaryl group can be linear, branched, saturated, unsaturated, cyclic, and/or acyclic, and wherein hetero atoms, such as oxygen, nitrogen, sulfur, silicon, phosphorus, boron, and the like either may or may not be present in either or both of the alkyl portion and the aryl portion of the alkylaryl group), in one embodiment with at least about 6 carbon atoms, in another embodiment with at least about 7 carbon atoms, and in yet another embodiment with at least about 8 carbon atoms, and in one embodiment with no more than about 200 carbon atoms, in another embodiment with no more than about 150 carbon atoms, and in yet another embodiment with no more than about 100 carbon atoms, although the number of carbon atoms can be outside of these ranges, such as tolyl or the like, R_(d), R_(e), and R_(f) each, independently of the others, is (i) an alkyl group (including linear, branched, saturated, unsaturated, cyclic, acyclic, substituted, and unsubstituted alkyl groups, and wherein hetero atoms, such as oxygen, nitrogen, sulfur, silicon, phosphorus, boron, and the like either may or may not be present in the alkyl group), in one embodiment with at least 1 carbon atom, in another embodiment with at least about 2 carbon atoms, in yet another embodiment with at least about 6 carbon atoms, in another embodiment with at least about 17 carbon atoms, and in yet another embodiment with at least about 36 carbon atoms, and in one embodiment with no more than about 200 carbon atoms, in another embodiment with no more than about 150 carbon atoms, and in yet another embodiment with no more than about 100 carbon atoms, although the number of carbon atoms can be outside of these ranges, (ii) an aryl group (including unsubstituted and substituted aryl groups, and wherein hetero atoms, such as oxygen, nitrogen, sulfur, silicon, phosphorus, boron, and the like either may or may not be present in the aryl group), in one embodiment with at least about 6 carbon atoms, in another embodiment with at least about 10 carbon atoms, and in yet another embodiment with at least about 14 carbon atoms, and in one embodiment with no more than about 200 carbon atoms, in another embodiment with no more than about 150 carbon atoms, and in yet another embodiment with no more than about 100 carbon atoms, although the number of carbon atoms can be outside of these ranges, (iii) an arylalkyl group (including unsubstituted and substituted arylalkyl groups, wherein the alkyl portion of the arylalkyl group can be linear, branched, saturated, unsaturated, cyclic, and/or acyclic, and wherein hetero atoms, such as oxygen, nitrogen, sulfur, silicon, phosphorus, boron, and the like either may or may not be present in either or both of the alkyl portion and the aryl portion of the arylalkyl group), in one embodiment with at least about 6 carbon atoms, in another embodiment with at least about 7 carbon atoms, and in yet another embodiment with at least about 8 carbon atoms, and in one embodiment with no more than about 200 carbon atoms, in another embodiment with no more than about 150 carbon atoms, and in yet another embodiment with no more than about 100 carbon atoms, although the number of carbon atoms can be outside of these ranges, such as benzyl or the like, or (iv) an alkylaryl group (including unsubstituted and substituted alkylaryl groups, wherein the alkyl portion of the alkylaryl group can be linear, branched, saturated, unsaturated, cyclic, and/or acyclic, and wherein hetero atoms, such as oxygen, nitrogen, sulfur, silicon, phosphorus, boron, and the like either may or may not be present in either or both of the alkyl portion and the aryl portion of the alkylaryl group), in one embodiment with at least about 6 carbon atoms, in another embodiment with at least about 7 carbon atoms, and in yet another embodiment with at least about 8 carbon atoms, and in one embodiment with no more than about 200 carbon atoms, in another embodiment with no more than about 150 carbon atoms, and in yet another embodiment with no more than about 100 carbon atoms, although the number of carbon atoms can be outside of these ranges, such as tolyl or the like, those generated from branched triacids, said branched triamides being of the formula

wherein R₂ is (i) an alkylene group (including linear, branched, saturated, unsaturated, cyclic, acyclic, substituted, and unsubstituted alkylene groups, and wherein hetero atoms, such as oxygen, nitrogen, sulfur, silicon, phosphorus, boron, and the like either may or may not be present in the alkylene group), in one embodiment with at least about 3 carbon atoms, in another embodiment with at least about 4 carbon atoms, in yet another embodiment with at least about 5 carbon atoms, in another embodiment with at least about 15 carbon atoms, and in yet another embodiment with at least about 21 carbon atoms, and in on e embodiment with no more than about 200 carbon atoms, in another embodiment with no more than about 150 carbon atoms, and in yet another embodiment with no more than about 100 carbon atoms, although the number of carbon atoms can be outside of these ranges, (ii) an arylene group (including unsubstituted and substituted arylene groups, and wherein hetero atoms, such as oxygen, nitrogen, sulfur, silicon, phosphorus, boron, and the like either may or may not be present in the arylene group), in one embodiment with at least about 6 carbon atoms, in another embodiment with at least about 10 carbon atoms, and in yet another embodiment with at least about 14 carbon atoms, and in one embodiment with no more than about 200 carbon atoms, in another embodiment with no more than about 150 carbon atoms, and in yet another embodiment with no more than about 100 carbon atoms, although the number of carbon atoms can be outside of these ranges, (iii) an arylalkylene group (including unsubstituted and substituted arylalkylene groups, wherein the alkyl portion of the arylalkylene group can be linear, branched, saturated, unsaturated, cyclic, and/or acyclic, and wherein hetero atoms, such as oxygen, nitrogen, sulfur, silicon, phosphorus, boron, and the like either may or may not be present in either or both of the alkyl portion and the aryl portion of the arylalkylene group), in one embodiment with at least about 7 carbon atoms, in another embodiment with at least about 8 carbon atoms, and in yet another embodiment with at least about 9 carbon atoms, and in one embodiment with no more than about 200 carbon atoms, in another embodiment with no more than about 150 carbon atoms, and in yet another embodiment with no more than about 100 carbon atoms, although the number of carbon atoms can be outside of these ranges, such as benzylene or the like, or (iv) an alkylarylene group (including unsubstituted and substituted alkylarylene groups, wherein the alkyl portion of the alkylarylene group can be linear, branched, saturated, unsaturated, cyclic, and/or acyclic, and wherein hetero atoms, such as oxygen, nitrogen, sulfur, silicon, phosphorus, boron, and the like either may or may not be present in either or both of the alkyl portion and the aryl portion of the alkylarylene group), in one embodiment with at least about 7 carbon atoms, in another embodiment with at least about 8 carbon atoms, and in yet another embodiment with at least about 9 carbon atoms, and in one embodiment with no more than about 200 carbon atoms, in another embodiment with no more than about 150 carbon atoms, and in yet another embodiment with no more than about 100 carbon atoms, although the number of carbon atoms can be outside of these ranges, such as tolylene or the like, R_(g), R_(j), and R_(p) each, independently of the others, is (i) a hydrogen atom, (ii) an alkyl group (including linear, branched, saturated, unsaturated, cyclic, acyclic, substituted, and unsubstituted alkyl groups, and wherein hetero atoms, such as oxygen, nitrogen, sulfur, silicon, phosphorus, boron, and the like either may or may not be present in the alkyl group), in one embodiment with at least about 1 carbon atom, in another embodiment with at least about 2 carbon atoms, in yet another embodiment with at least about 3 carbon atoms, in another embodiment with at least about 6 carbon atoms, and in yet another embodiment with at least about 18 carbon atoms, and in one embodiment with no more than about 200 carbon atoms, in another embodiment with no more than about 150 carbon atoms, and in yet another embodiment with no more than about 100 carbon atoms, although the number of carbon atoms can be outside of these ranges, (iii) an aryl group (including unsubstituted and substituted aryl groups, and wherein hetero atoms, such as oxygen, nitrogen, sulfur, silicon, phosphorus, boron, and the like either may or may not be present in the aryl group), in one embodiment with at least about 6 carbon atoms, in another embodiment with at least about 10 carbon atoms, and in yet another embodiment with at least about 14 carbon atoms, and in one embodiment with no more than about 200 carbon atoms, in another embodiment with no more than about 150 carbon atoms, and in yet another embodiment with no more than about 100 carbon atoms, although the number of carbon atoms can be outside of these ranges, (iv) an arylalkyl group (including unsubstituted and substituted arylalkyl groups, wherein the alkyl portion of the arylalkyl group can be linear, branched, saturated, unsaturated, cyclic, and/or acyclic, and wherein hetero atoms, such as oxygen, nitrogen, sulfur, silicon, phosphorus, boron, and the like either may or may not be present in either or both of the alkyl portion and the aryl portion of the arylalkyl group), in one embodiment with at least about 7 carbon atoms, in another embodiment with at least about 8 carbon atoms, and in yet another embodiment with at least about 9 carbon atoms, and in one embodiment with no more than about 200 carbon atoms, in another embodiment with no more than about 150 carbon atoms, and in yet another embodiment with no more than about 100 carbon atoms, although the number of carbon atoms can be outside of these ranges, such as benzyl or the like, or (v) an alkylaryl group (including unsubstituted and substituted alkylaryl groups, wherein the alkyl portion of the alkylaryl group can be linear, branched, saturated, unsaturated, cyclic, and/or acyclic, and wherein hetero atoms, such as oxygen, nitrogen, sulfur, silicon, phosphorus, boron, and the like either may or may not be present in either or both of the alkyl portion and the aryl portion of the alkylaryl group), in one embodiment with at least about 7 carbon atoms, in another embodiment with at least about 8 carbon atoms, and in yet another embodiment with at least about 9 carbon atoms, and in one embodiment with no more than about 200 carbon atoms, in another embodiment with no more than about 150 carbon atoms, and in yet another embodiment with no more than about 100 carbon atoms, although the number of carbon atoms can be outside of these ranges, such as tolyl or the like, R_(h), R_(k), and R_(q) each, independently of the others, is (i) a hydrogen atom, (ii) an alkyl group (including linear, branched, saturated, unsaturated, cyclic, acyclic, substituted, and unsubstituted alkyl groups, and wherein hetero atoms, such as oxygen, nitrogen, sulfur, silicon, phosphorus, boron, and the like either may or may not be present in the alkyl group), in one embodiment with at least about 1 carbon atom, in another embodiment with at least about 2 carbon atoms, in yet another embodiment with at least about 3 carbon atoms, in another embodiment with at least about 4 carbon atoms, and in yet another embodiment with at least about 5 carbon atoms, and in one embodiment with no more than about 200 carbon atoms, in another embodiment with no more than about 150 carbon atoms, and in yet another embodiment with no more than about 100 carbon atoms, although the number of carbon atoms can be outside of these ranges, (iii) an aryl group (including unsubstituted and substituted aryl groups, and wherein hetero atoms, such as oxygen, nitrogen, sulfur, silicon, phosphorus, boron, and the like either may or may not be present in the aryl group), in one embodiment with at least about 6 carbon atoms, in another embodiment with at least about 7 carbon atoms, and in yet another embodiment with at least about 8 carbon atoms, and in one embodiment with no more than about 200 carbon atoms, in another embodiment with no more than about 150 carbon atoms, and in yet another embodiment with no more than about 100 carbon atoms, although the number of carbon atoms can be outside of these ranges, (iv) an arylalkyl group (including unsubstituted and substituted arylalkyl groups, wherein the alkyl portion of the arylalkyl group can be linear, branched, saturated, unsaturated, cyclic, and/or acyclic, and wherein hetero atoms, such as oxygen, nitrogen, sulfur, silicon, phosphorus, boron, and the like either may or may not be present in either or both of the alkyl portion and the aryl portion of the arylalkyl group), in one embodiment with at least about 7 carbon atoms, in another embodiment with at least about 8 carbon atoms, and in yet another embodiment with at least about 9 carbon atoms, and in one embodiment with no more than about 200 carbon atoms, in another embodiment with no more than about 150 carbon atoms, and in yet another embodiment with no more than about 100 carbon atoms, although the number of carbon atoms can be outside of these ranges, such as benzyl or the like, or (v) an alkylaryl group (including unsubstituted and substituted alkylaryl groups, wherein the alkyl portion of the alkylaryl group can be linear, branched, saturated, unsaturated, cyclic, and/or acyclic, and wherein hetero atoms, such as oxygen, nitrogen, sulfur, silicon, phosphorus, boron, and the like either may or may not be present in either or both of the alkyl portion and the aryl portion of the alkylaryl group), in one embodiment with at least about 7 carbon atoms, in another embodiment with at least about 8 carbon atoms, and in yet another embodiment with at least about 9 carbon atoms, and in one embodiment with no more than about 200 carbon atoms, in another embodiment with no more than about 150 carbon atoms, and in yet another embodiment with no more than about 100 carbon atoms, although the number of carbon atoms can be outside of these ranges, such as tolyl or the like, those generated from branched diamino monoacid compounds, said branched triamides being of the formula

wherein R₁, R_(a), R_(b), R_(d), R_(e), R_(g), and R_(h) are as defined hereinabove, those generated from branched monoamino diacid compounds, said branched triamides being of the formula

wherein R₂, R_(a), R_(d), R_(g), R_(h), R_(j), and R_(k) are as defined hereinabove, and the like, wherein the substituents on the substituted alkyl, alkylene, aryl, arylene, arylalkyl, arylalkylene, alkylaryl, and alkylarylene groups can be (but are not limited to) hydroxy groups, halogen atoms, imine groups, ammonium groups, cyano groups, pyridine groups, pyridinium groups, ether groups, aldehyde groups, ketone groups, ester groups, carbonyl groups, thiocarbonyl groups, sulfate groups, sulfonate groups, sulfonic acid groups, sulfide groups, sulfoxide groups, phosphine groups, phosphonium groups, phosphate groups, nitrile groups, mercapto groups, nitro groups, nitroso groups, sulfone groups, azide groups, azo groups, cyanato groups, carboxylate groups, mixtures thereof, and the like, wherein two or more substituents can be joined together to form a ring.

In one specific embodiment, when the triamide is of the formula

the total number of carbon atoms in R₁+R_(a)+R_(b)+R_(c)+R_(d)+R_(e)+R_(f) is at least about 7, in another embodiment at least about 10, and in yet another embodiment at least about 12, and in one embodiment no more than about 500, in another embodiment no more than about 350, and in yet another embodiment no more than about 300, although the total number of carbon atoms can be outside of these ranges. In another specific embodiment, each of R_(a), R_(d), R_(b), R_(e), R_(c), and R_(f), independently of the others, has no more than about 50 carbon atoms, and in yet another specific embodiment no more than about 48 carbon atoms, although the number of carbon atoms can be outside of these ranges.

In one specific embodiment, when the triamide is of the formula

the total number of carbon atoms in R₂+R_(g)+R_(h)+R_(j)+R_(k)+R_(p)+R_(q) is at least about 7, in another embodiment at least about 10, and in yet another embodiment at least about 12, and in one embodiment no more than about 500, in another embodiment no more than about 350, and in yet another embodiment no more than about 300, although the total number of carbon atoms can be outside of these ranges. In another specific embodiment, each of R_(g), R_(h), R_(j), R_(k), R_(p), and R_(q), independently of the others, has no more than about 50 carbon atoms, and in yet another specific embodiment no more than about 48 carbon atoms, although the number of carbon atoms can be outside of these ranges.

In one specific embodiment, when the triamide is of the formula

the total number of carbon atoms in R₁+R_(a)+R_(b)+R_(d)+R_(e)+R_(g)+R_(h) is at least about 7, in another embodiment at least about 10, and in yet another embodiment at least about 12, and in one embodiment no more than about 500, in another embodiment no more than about 350, and in yet another embodiment no more than about 300, although the total number of carbon atoms can be outside of these ranges. In another specific embodiment, each of R_(a), R_(d), R_(b), R_(e), R_(g), and R_(h), independently of the others, has no more than about 50 carbon atoms, and in yet another specific embodiment no more than about 48 carbon atoms, although the number of carbon atoms can be outside of these ranges.

In one specific embodiment, when the triamide is of the formula

the total number of carbon atoms in R₂+R_(a)+R_(d)+R_(g)+R_(h)+R_(j)+R_(k) is at least about 7, in another embodiment at least about 10, and in yet another embodiment at least about 12, and in one embodiment no more than about 500, in another embodiment no more than about 350, and in yet another embodiment no more than about 300, although the total number of carbon atoms can be outside of these ranges. In another specific embodiment, each of R_(a), R_(d), R_(g), R_(h), R_(j), and R_(k), independently of the others, has no more than about 50 carbon atoms, and in yet another specific embodiment no more than about 48 carbon atoms, although the number of carbon atoms can be outside of these ranges.

It must be emphasized that not all of the amide groups in the first formula need to be directly bonded to the same atom in the R₁ or R₂ group, and in one specific embodiment of the present invention, each amide group is bonded to a different atom in the R₁ or R₂ group.

In one specific embodiment, the branched triamide is of the formula

wherein x, y, and z each, independently represent the number of propyleneoxy repeat units and x+y+z is from about 5 to about 6, and wherein p, q, and r each, independently of the others, are integers representing the number of repeat —(CH₂)— units and are in one embodiment at least about 15, in another embodiment is at least about 20, and in another embodiment is at least about 26, and are one embodiment no more than about 60, in another embodiment are no more than about 55, and are in yet another embodiment no more than about 45, although the value of p, q, and r can be outside of these ranges. The triamide composition is frequently obtained as a mixture of materials, wherein p, q, and r are each peak average chain length numbers within the composition, rather than uniform compositions wherein each molecule has the same value for p, q, and r, and it must be understood that within the mixture, some individual chains may be longer or shorter than the given numbers.

The triamide is present in the ink in any desired or effective amount, in one embodiment at least about 2 percent by weight of the phase change ink carrier, in another embodiment at least about 5 percent by weight of carrier, and in yet another embodiment at least about 10 percent by weight of the carrier, and in one embodiment no more than about 50 percent by weight of the carrier, in another embodiment no more than about 40 percent by weight of the carrier, and in yet another embodiment no more than about 35 percent by weight of the carrier, although the amount can be outside of these ranges.

The polyethylene wax in one specific embodiment has an average peak molecular weight, as measured by high temperature gel permeation chromatography, of in one embodiment at least about 350, in another embodiment at least about 400, and in yet another embodiment at least about 470, and in one embodiment no more than about 730, in another embodiment no more than about 700, and in yet another embodiment no more than about 600, although the average peak molecular weight can be outside of these ranges.

The polyethylene wax in one specific embodiment has a polydispersity (determined by dividing weight average molecular weight by number average molecular weight) in one embodiment of at least about 1.0001, and in one embodiment of no more than about 1.500, in another embodiment of no more than about 1.400, in yet another embodiment of no more than about 1.300, in still another embodiment of no more than about 1.200, in another embodiment of no more than about 1.100, and in yet another embodiment of no more than about 1.050, although the polydispersity can be outside of these ranges.

The polyethylene wax in one specific embodiment has a peak melting point (as measured by differential scanning calorimetry (DSC)) in one embodiment of at least about 50° C., in another embodiment at least about 60° C., and in yet another embodiment of at least about 70° C., and in one embodiment of no more than about 130° C., in another embodiment of no more than about 125° C., and in yet another embodiment of no more than about 120° C., although the peak melting point can be outside of these ranges.

The polyethylene wax in one specific embodiment has an onset melting point (as measured by differential scanning calorimetry (DSC)) in one embodiment of at least about 50° C., in another embodiment at least about 52° C., and in yet another embodiment of at least about 55° C., and in one embodiment of no more than about 71° C., in another embodiment of no more than about 70° C., and in yet another embodiment of no more than about 69° C., although the onset melting point can be outside of these ranges.

The polyethylene wax in one specific embodiment has a melting range, which is defined as the difference between ending melting point and onset melting point as defined in ASTM D3418-03, in one embodiment of at least about 5° C., in another embodiment at least about 8° C., and in yet another embodiment of at least about 10° C., and in one embodiment of no more than about 40° C., in another embodiment of no more than about 35° C., and in yet another embodiment of no more than about 30° C., although the melting range can be outside of these ranges.

The polyethylene wax in one specific embodiment has a freezing point (as measured by differential scanning calorimetry (DSC)) in one embodiment of at least about 40° C., in another embodiment at least about 50° C., and in yet another embodiment of at least about 55° C., and in one embodiment of no more than about 80° C., in another embodiment of no more than about 75° C., and in yet another embodiment of no more than about 70° C., although the freezing point can be outside of these ranges.

Fischer-Tropsch waxes can be prepared from the hydrogen and carbon monoxide mixture obtained by passing steam over hot coal. The synthesis can be carried out with metallic catalysts at high temperature and pressure. They are synthetic hydrocarbons, as opposed to natural hydrocarbons. They differ from polyethylene waxes, which are prepared by the polymerization of ethylene (CH₂═CH₂) in that polyethylene waxes tend to be completely linear, whereas Fischer-Tropsch waxes tend to have some degree of branching therein. Because of this branching, Fischer-Tropsch waxes tend to be somewhat less crystalline and somewhat less hard compared to the perfectly linear polyethylene waxes.

Fischer-Tropsch waxes included in the inks disclosed herein have an average peak molecular weight, as measured by high temperature gel permeation chromatography, of in one embodiment at least about 300, in another embodiment at least about 375, and in yet another embodiment at least about 400, and in one embodiment no more than about 800, in another embodiment no more than about 750, and in yet another embodiment no more than about 700, although the average peak molecular weight can be outside of these ranges.

The Fischer-Tropsch wax has a polydispersity (determined by dividing weight average molecular weight by number average molecular weight) in one embodiment of at least about 1.001, in another embodiment of at least about 1.005, and in yet another embodiment of at least about 1.010, and in one embodiment of no more than about 3, in another embodiment of no more than about 2.5, and in yet another embodiment of no more than about 2, although the polydispersity can be outside of these ranges.

The Fischer-Tropsch wax has a peak melting point (as measured by differential scanning calorimetry (DSC)) in one embodiment of at least about 50° C., in another embodiment at least about 55° C., and in yet another embodiment of at least about 60° C., and in one embodiment of no more than about 105° C., in another embodiment of no more than about 100° C., and in yet another embodiment of no more than about 95° C., although the peak melting point can be outside of these ranges.

The Fischer-Tropsch wax has an onset melting point (as measured by differential scanning calorimetry (DSC)) in one embodiment of at least about 40° C., in another embodiment at least about 45° C., and in yet another embodiment of at least about 50° C., and in one embodiment of no more than about 105° C., in another embodiment of no more than about 100° C., and in yet another embodiment of no more than about 95° C., although the onset melting point can be outside of these ranges.

The Fischer-Tropsch wax has a melting range, which is defined as the difference between ending melting point and onset melting point as defined in ASTM D3418-03, in one embodiment of at least about 5° C., in another embodiment at least about 8° C., and in yet another embodiment of at least about 10° C., and in one embodiment of no more than about 40° C., in another embodiment of no more than about 30° C., and in yet another embodiment of no more than about 25° C., although the melting range can be outside of these ranges.

The Fischer-Tropsch wax has a freezing point (as measured by differential scanning calorimetry (DSC)) in one embodiment of at least about 40° C., in another embodiment at least about 50° C., and in yet another embodiment of at least about 55° C., and in one embodiment of no more than about 90° C., in another embodiment of no more than about 88° C., and in yet another embodiment of no more than about 85° C., although the freezing point can be outside of these ranges.

The polyethylene or Fischer-Tropsch wax in one specific embodiment has a viscosity at about 110° C. in one embodiment of at least about 3 centipoise, in another embodiment of at least about 4 centipoise, and in yet another embodiment of at least about 4.5 centipoise, and in one embodiment of no more than about 10 centipoise, in another embodiment of no more than about 9 centipoise, and in yet another embodiment of no more than about 8 centipoise, although the viscosity can be outside of these ranges.

By “average peak molecular weight” is meant that the polyethylene or Fischer-Tropsch wax, while comprising a mixture of molecules of the formula —(CH₂)_(n)— wherein n is an integer representing the number of repeat —CH₂— units, has a distribution of molecules such that a plot of the relative amount of molecules versus the retention time or molecular weight would appear as a bell curve, wherein the peak of the bell curve represents the average peak molecular weight. In contrast, polyethylene or Fischer-Tropsch waxes having a different average peak molecular weight value, while they may contain materials that overlap in the value of “n”, will have different characteristics.

Shown in the Figure are measurements of molecular weight taken for some polyethylene waxes and some Fischer-Tropsch waxes by high temperature gel permeation chromatography with a Polymer Labs 220HT system using refractive index detection, a mobile phase of 1,2,4-trichlorobenzene, and two Polymer 3 μm Mixed-E columns for separation. The entire system and the sample solution before injection were heated to 140° C. The molecular weights were characterized using polyethylene standards for calibration. One material (PE500) was a polyethylene wax commercially available from Baker Petrolite, Tulsa, Okla., being POLYWAX® 500 (PE 500). Also measured was a polyethylene wax commercially available from Baker Petrolite, Tulsa, Okla., being POLYWAX® 655 (PE655). Also measured was a polyethylene wax commercially available from Baker Petrolite, Tulsa, Okla., having a molecular weight of about 655 (PE655). Also measured (PE-C) was a polyethylene wax obtained from Baker Petrolite, Tulsa, Okla., being similar to POLYWAX® 500 but having had removed by distillation both the lowest 15 percent molecular weight fraction and the highest 15 percent molecular weight fraction. This distillation can be carried out as described in, for example, U.S. Patent Publication 2005/0130054, the disclosure of which is totally incorporated herein by reference. Also measured (FT-B) was a Fischer-Tropsch wax commercially available from Sasol Wax Americas, Inc. as SASOLWAX® C80, said wax having been fractioned by distillation. Also measured (FT-C) was a Fischer-Tropsch wax obtained from Sasol Wax Americas, Inc., said wax being similar to SASOLWAX® C80 but having had removed by distillation the lowest 9 percent molecular weight fraction. Also measured (FT-D) was a Fischer-Tropsch wax obtained from Sasol Wax Americas, Inc., said wax being similar to SASOLWAX® C80 but having had removed by distillation the lowest 20 percent molecular weight fraction. Also measured (FT-E) was a Fischer-Tropsch wax obtained from Sasol Wax Americas, Inc., said wax being similar to SASOLWAX® C80 but having had removed by distillation the lowest 30 percent molecular weight fraction.

retention times (sec.) PE 500 PE 655 PE-C FT-B FT-C FT-D FT-E 750 0.1 −0.7 −0.9 −0.8 −0.7 −0.1 −1.1 755 0.2 −0.6 −0.9 −0.8 −0.7 −0.1 −1.1 760 0.2 −0.4 −0.9 −0.8 −0.7 −0.1 −1.1 765 0.2 −0.1 −0.9 −0.7 −0.7 −0.1 −1.0 770 0.3 0.1 −0.9 −0.6 −0.7 −0.1 −1.0 775 0.3 0.6 −0.9 −0.6 −0.7 −0.1 −1.0 780 0.4 1.2 −0.9 −0.5 −0.7 0.0 −1.0 785 0.6 2.1 −0.9 −0.5 −0.7 0.0 −1.0 790 0.8 3.6 −0.9 −0.4 −0.7 0.0 −1.0 795 1.0 6.0 −1.0 −0.3 −0.6 0.0 −1.0 800 1.3 9.7 −1.0 −0.3 −0.6 0.1 −1.0 805 1.8 14.8 −1.0 −0.2 −0.6 0.1 −0.9 810 2.3 21.8 −1.0 −0.1 −0.5 0.2 −0.8 815 3.2 30.6 −1.0 0.1 −0.4 0.3 −0.7 820 4.5 41.1 −1.0 0.2 −0.2 0.6 −0.4 825 6.3 52.6 −0.9 0.5 0.2 1.0 0.0 830 8.9 64.5 −0.9 0.8 0.8 1.7 0.8 835 12.6 75.9 −0.7 1.4 2.1 3.1 2.3 840 17.6 85.8 −0.3 2.5 4.4 5.6 5.0 845 24.1 93.5 0.6 4.4 8.3 9.8 9.6 850 32.0 98.3 2.8 7.6 14.6 16.5 16.8 855 41.3 100.0 7.0 12.6 23.9 26.7 27.6 860 51.4 98.6 14.4 20.0 36.9 40.5 42.3 865 61.9 94.3 26.0 30.0 52.9 57.3 59.9 870 72.2 87.8 41.3 42.3 70.2 75.1 77.9 875 81.7 79.7 58.7 56.2 86.0 90.2 92.4 880 89.6 70.6 75.3 70.1 96.7 98.9 99.6 881 90.9 68.8 78.2 72.8 98.0 99.6 100.0 882 92.2 66.9 81.0 75.5 99.0 100.0 99.9 884 94.5 63.1 86.1 80.6 100.0 99.5 98.7 885 95.5 61.2 88.4 83.1 99.9 98.8 97.6 890 99.0 52.0 96.6 93.6 94.9 89.9 87.2 891 99.4 50.3 97.7 95.3 93.0 87.2 84.4 895 100.0 43.4 99.9 99.6 82.5 74.4 71.3 896.5 99.8 41.0 100.0 100.0 77.7 69.0 65.9 900 98.6 35.7 98.5 97.3 64.9 55.9 53.1 905 95.0 28.7 93.4 84.0 45.3 37.6 35.5 910 89.7 22.8 84.9 62.9 27.3 22.2 20.8 910.5 89.1 22.2 83.9 60.7 25.7 20.9 19.5 915 82.8 17.9 73.2 42.5 13.9 11.5 10.4 920 75.0 13.9 60.1 28.1 6.0 5.3 4.3 925 67.4 10.5 46.3 19.4 2.4 2.5 1.5 930 58.8 8.0 32.7 13.9 0.9 1.4 0.4 935 51.2 5.7 22.0 9.5 0.4 1.0 0.0 940 43.9 4.3 13.2 5.6 0.1 0.8 −0.2 945 36.7 2.9 7.7 2.7 −0.1 0.7 −0.4 950 31.3 2.0 3.9 1.1 −0.2 0.6 −0.5 955 25.2 1.2 2.0 0.3 −0.3 0.5 −0.5 960 21.4 0.8 0.7 −0.1 −0.4 0.5 −0.6 965 16.9 0.2 0.1 −0.3 −0.4 0.4 −0.7 970 13.5 0.1 −0.4 −0.3 −0.5 0.4 −0.7 975 11.4 −0.3 −0.6 −0.3 −0.6 0.3 −0.8 980 7.4 −0.4 −0.8 −0.3 −0.6 0.2 −0.8 985 6.8 −0.6 −0.9 −0.3 −0.7 0.2 −0.9 990 4.4 −0.8 −1.0 −0.4 −0.7 0.2 −0.9 995 2.9 −0.7 −1.0 −0.6 −0.8 0.1 −1.0 1000 2.6 −0.9 −1.0 −0.8 −0.8 0.1 −1.0 1005 1.5 −0.9 −1.1 −0.9 −0.8 0.1 −1.1 1010 0.9 −0.9 −1.1 −1.0 −0.9 0.1 −1.1 1015 0.9 −0.9 −1.1 −1.0 −0.9 0.1 −1.1 1020 0.6 −1.1 −1.1 −1.1 −0.9 0.1 −1.1 1025 0.4 −1.1 −1.2 −1.2 −0.9 0.1 −1.1 1030 0.4 −1.5 −1.2 −1.4 −0.8 0.1 −1.0 1035 0.7 −2.0 −1.4 −1.7 −0.8 0.2 −0.9 1040 0.9 −2.2 −1.8 −1.7 −0.6 0.4 −0.7 1045 0.8 −1.6 −1.8 −1.5 0.0 1.0 −0.2 As measured by high temperature gel permeation chromatography, the peak average molecular weight (M_(p)), number average molecular weight (M_(n)), weight average molecular weight (M_(w)), and polydispersity (MWD) as measured by high temperature gel permeation chromatography for these waxes were as follows:

M_(p) M_(n) M_(w) MWD PE 500 572 516 570 1.10 PE 655 795 729 785 1.08 PE-C 582 562 579 1.03 FT-B 558 565 588 1.04 FT-C 620 619 635 1.03 FT-D 631 627 643 1.03 FT-E 637 630 646 1.03 Peak melting point (° C., as measured by differential scanning calorimetry using a DUPONT 2100 calorimeter according to ASTM D 3418-03), onset melting point (° C., as measured by differential scanning calorimetry), viscosity at 110° C. (centipoise, measured using a Rheometric Scientific RS-2000 core-plate viscometer), and freezing point (° C., as measured by differential scanning calorimetry) of the high temperature gel permeation chromatography data of these waxes were as follows:

peak MP onset MP melting range viscosity FP PE 500 81.2 52.5 42.2 5.44 70.3 PE 655 94.6 72.3 29.6~33.0 9.80 85.5 PE-C 83.8 65.5 24.1 5.18 67.4 FT-B 82.1 69.5 22.1 5.53 70.1 FT-C 85.1 73.3 17.1 6.09 76.6 FT-D 86.1 74.5 16.2 6.26 78.2 FT-E 86.7 74.6 17.7 6.33 77.6 — = not measured or determined

Melted liquid clearness of the waxes was evaluated by melting samples of the waxes in glass jars and keeping them in an oven at various temperatures, followed by checking them with the naked eye for clearness versus the presence of precipitates over time. The results were as follows:

PE 500 PE-C 1 day at 120° C. clear clear 3 days at 110° C. a little precipitate clear 6 days at 105° C. a little precipitate clear 11 days at 100° C. a little precipitate clear The results clearly indicate the advantage of the wax having had both the low molecular weight fraction and the high molecular weight fraction removed in that no precipitates form therein even after 11 days. The cloudiness is believed to indicate the presence of precipitates responsible for printhead clogging, which results in reduced ink flow rate through screen filters in ink jet printhead, which in turn causes weak or missing jets.

The polyethylene wax in the inks disclosed herein have had some of the lowest molecular weight fraction removed therefrom and some of the highest molecular weight fraction removed therefrom, in one embodiment at least about the lowest 5 percent molecular weight fraction removed therefrom, in another embodiment at least about the lowest 7.5 percent molecular weight fraction removed therefrom, in yet another embodiment at least about the lowest 10 percent molecular weight fraction removed therefrom, in still another embodiment, at least about the lowest 12.5 molecular weight fraction removed therefrom, and in yet still another embodiment at least about the lowest 15 percent molecular weight fraction removed therefrom, and in one embodiment least about the highest 5 percent molecular weight fraction removed therefrom, in another embodiment at least about the highest 7.5 percent molecular weight fraction removed therefrom, in yet another embodiment at least about the highest 10 percent molecular weight fraction removed therefrom, in still another embodiment, at least about the highest 12.5 molecular weight fraction removed therefrom, and in yet still another embodiment at least about the highest 15 percent molecular weight fraction removed therefrom, although the amount removed therefrom can be outside of these ranges.

In some specific embodiments, the Fischer-Tropsch wax in the inks disclosed herein have had some of the lowest molecular weight fraction removed therefrom, in one embodiment at least about the lowest 5 percent molecular weight fraction removed therefrom, in another embodiment at least about the lowest 7.5 percent molecular weight fraction removed therefrom, in yet another embodiment at least about the lowest 10 percent molecular weight fraction removed therefrom, in still another embodiment, at least about the lowest 12.5 molecular weight fraction removed therefrom, in another embodiment at least about the lowest 15 percent molecular weight fraction removed therefrom, in yet another embodiment at least about the lowest 20 percent molecular weight fraction removed therefrom, in still another embodiment at least about the lowest 25 percent molecular weight fraction removed therefrom, in another embodiment at least about the lowest 30 percent molecular weight fraction removed therefrom, and in yet another embodiment at least about the lowest 35 percent molecular weight fraction removed therefrom, although the amount removed therefrom can be outside of these ranges.

The lowest molecular weight fraction and the highest molecular weight fraction can be removed from the polyethylene or Fischer-Tropsch wax by any desired or effective method, including (but not limited to) the distillation methods described in U.S. Patent Publication 2005/0130054, the disclosure of which is totally incorporated herein by reference, the purification methods set forth in Copending application Ser. No. 11/126,745, the disclosure of which is totally incorporated herein by reference, or the like.

As stated hereinabove, the Fischer-Tropsch process used to generate the Fischer-Tropsch waxes differs from the polymerization of ethylene process used to generate polyethylene waxes in that the Fischer-Tropsch process tends to generate more branching in the resulting materials. ¹³C and ¹H NMR spectra were used to measure the branching extent and number of pendant —OH groups in some of the Fischer-Tropsch and polyethylene waxes. Samples were dissolved in deuterated benzene and ¹³C NMR spectra were obtained on a Bruker Avance 400 NMR spectrometer at 78° C. In addition, DEPT (distortionless enhancement by polarization transfer) experiments were carried out to distinguish CH, CH₂, and CH₃ carbons as an aid to spectral assignment. ¹H NMR measurements were made on the same samples on a Bruker Avance 500 NMR spectrometer at 78° C. The results were as follows:

# isolated long # methyl # pendant —OH branches per 100 branches per 100 groups per 100 Wax chains chains chains PE 500 trace 0 trace PE-C 0 1 1.2 FT-B 1.2 6.4 0

The polyethylene wax is present in the ink in any desired or effective amount, in one embodiment at least about 10 percent by weight of the phase change ink carrier, in another embodiment at least about 15 percent by weight of carrier, and in yet another embodiment at least about 20 percent by weight of the carrier, and in one embodiment no more than about 95 percent by weight of the carrier, in another embodiment no more than about 90 percent by weight of the carrier, and in yet another embodiment no more than about 85 percent by weight of the carrier, although the amount can be outside of these ranges.

The Fischer-Tropsch wax is present in the ink in any desired or effective amount, in one embodiment at least about 1 percent by weight of the phase change ink carrier, in another embodiment at least about 3 percent by weight of carrier, and in yet another embodiment at least about 5 percent by weight of the carrier, and in one embodiment no more than about 99 percent by weight of the carrier, in another embodiment no more than about 97 percent by weight of the carrier, and in yet another embodiment no more than about 95 percent by weight of the carrier, although the amount can be outside of these ranges.

Additional examples of suitable phase change ink carrier materials are monoamides, tetra-amides, mixtures thereof, and the like. Specific examples of suitable fatty amide ink carrier materials include stearyl stearamide, such as KEMAMIDE S-180, available from Crompton Corporation, Greenwich, Conn., and the like. Further information on fatty amide carrier materials is disclosed in, for example, U.S. Pat. No. 4,889,560, U.S. Pat. No. 4,889,761, U.S. Pat. No. 5,194,638, U.S. Pat. No. 4,830,671, U.S. Pat. No. 6,174,937, U.S. Pat. No. 5,372,852, U.S. Pat. No. 5,597,856, U.S. Pat. No. 6,174,937, and British Patent GB 2 238 792, the disclosures of each of which are totally incorporated herein by reference. In one specific embodiment, a monoamide is present in the ink carrier in an amount in one embodiment of at least about 0.01 percent by weight of the carrier, in another embodiment of at least 2 percent by weight of the carrier, and in yet another embodiment of at least about 5 percent by weight of the carrier, and in one embodiment of no more than about 90 percent by weight of the carrier, in another embodiment of no more than about 80 percent by weight of the carrier, and in yet another embodiment of no more than about 70 percent by weight of the carrier, although the amount can be outside of these ranges.

Also suitable as phase change ink carrier materials are isocyanate-derived resins and waxes, such as urethane isocyanate-derived materials, urea isocyanate-derived materials, urethane/urea isocyanate-derived materials, mixtures thereof, and the like. Further information on isocyanate-derived carrier materials is disclosed in, for example, U.S. Pat. No. 5,750,604, U.S. Pat. No. 5,780,528, U.S. Pat. No. 5,782,966, U.S. Pat. No. 5,783,658, U.S. Pat. No. 5,827,918, U.S. Pat. No. 5,830,942, U.S. Pat. No. 5,919,839, U.S. Pat. No. 6,255,432, U.S. Pat. No. 6,309,453, British Patent GB 2 294 939, British Patent GB 2 305 928, British Patent GB 2 305 670, British Patent GB 2 290 793, PCT Publication WO 94/14902, PCT Publication WO 97/12003, PCT Publication WO 97/13816, PCT Publication WO 96/14364, PCT Publication WO 97/33943, and PCT Publication WO 95/04760, the disclosures of each of which are totally incorporated herein by reference.

In one specific embodiment, the ink can contain a urethane resin obtained from the reaction of two equivalents of ABITOL® E hydroabietyl alcohol (available from Hercules Inc., Wilmington, Del.) and one equivalent of isophorone diisocyanate, prepared as described in Example 1 of U.S. Pat. No. 5,782,966, the disclosure of which is totally incorporated herein by reference. When present, this resin is present in the ink in one embodiment in an amount of at least about 1 percent by weight of the ink carrier, in another embodiment at least about 2 percent by weight of the ink carrier, in yet another embodiment at least about 3 percent by weight of the ink carrier, in another embodiment at least about 4 percent by weight of the ink carrier, and in yet another embodiment at least about 5 percent by weight of the ink carrier, and in one embodiment no more than about 80 percent by weight of the ink carrier, in another embodiment no more than about 70 percent by weight of the ink carrier, and in yet another embodiment no more than about 60 percent by weight of the ink carrier, although the amount can be outside of these ranges.

In another specific embodiment, the ink can contain a urethane resin that is the adduct of three equivalents of stearyl isocyanate and a glycerol-based alcohol prepared as described in Example 4 of U.S. Pat. No. 6,309,453, the disclosure of which is totally incorporated herein by reference. When present, this resin is present in the ink in one embodiment in an amount of at least about 0.1 percent by weight of the ink carrier, in another embodiment at least about 0.5 percent by weight of the ink carrier, and in yet another embodiment at least about 1 percent by weight of the ink carrier, and in one embodiment no more than about 40 percent by weight of the ink carrier, in another embodiment no more than about 35 percent by weight of the ink carrier, and in yet another embodiment no more than about 30 percent by weight of the ink carrier, although the amount can be outside of these ranges.

The ink carrier is present in the phase change ink in any desired or effective amount, in one embodiment of at least about 0.1 percent by weight of the ink, in another embodiment of at least about 50 percent by weight of the ink, and in yet another embodiment of at least about 90 percent by weight of the ink, and in one embodiment of no more than about 99 percent by weight of the ink, in another embodiment of no more than about 98 percent by weight of the ink, and in yet another embodiment of no more than about 95 percent by weight of the ink, although the amount can be outside of these ranges.

The phase change ink compositions also contain a colorant. The phase change carrier compositions can be used in combination with phase change ink colorant materials such as Color Index (C.I.) Solvent Dyes, Disperse Dyes, modified Acid and Direct Dyes, Basic Dyes, Sulphur Dyes, Vat Dyes, and the like. Examples of suitable dyes include Neozapon Red 492 (BASF); Orasol Red G (Ciba-Geigy); Direct Brilliant Pink B (Crompton & Knowles); Aizen Spilon Red C-BH (Hodogaya Chemical); Kayanol Red 3BL (Nippon Kayaku); Levanol Brilliant Red 3BW (Mobay Chemical); Levaderm Lemon Yellow (Mobay Chemical); Spirit Fast Yellow 3G; Aizen Spilon Yellow C-GNH (Hodogaya Chemical); Sirius Supra Yellow GD 167; Cartasol Brilliant Yellow 4GF (Sandoz); Pergasol Yellow CGP (Ciba-Geigy); Orasol Black RLP (Ciba-Geigy); Savinyl Black RLS (Sandoz); Dermacarbon 2GT (Sandoz); Pyrazol Black BG (ICI); Morfast Black Conc. A (Morton-Thiokol); Diaazol Black RN Quad (ICI); Orasol Blue GN (Ciba-Geigy); Savinyl Blue GLS (Sandoz); Luxol Blue MBSN (Morton-Thiokol); Sevron Blue 5GMF (ICI); Basacid Blue 750 (BASF), Neozapon Black X51 (C.I. Solvent Black, C.I. 12195) (BASF), Sudan Blue 670 (C.I. 61554) (BASF), Sudan Yellow 146 (C.I. 12700) (BASF), Sudan Red 462 (C.I. 26050) (BASF), Intratherm Yellow 346 from Crompton and Knowles, C.I. Disperse Yellow 238, Neptune Red Base NB543 (BASF, C.I. Solvent Red 49), Neopen Blue FF-4012 from BASF, Lampronol Black BR from ICI (C.I. Solvent Black 35), Morton Morplas Magenta 36 (C.I. Solvent Red 172), metal phthalocyanine colorants such as those disclosed in U.S. Pat. No. 6,221,137, the disclosure of which is totally incorporated herein by reference, and the like. Polymeric dyes can also be used, such as those disclosed in, for example, U.S. Pat. No. 5,621,022 and U.S. Pat. No. 5,231,135, the disclosures of each of which are totally incorporated herein by reference, and commercially available from, for example, Milliken & Company as Milliken Ink Yellow 12, Milliken Ink Blue 92, Milliken Ink Red 357, Milliken Ink Yellow 1800, Milliken Ink Black 8915-67, uncut Reactant Orange X-38, uncut Reactant Blue X-17, Solvent Yellow 162, Acid Red 52, Solvent Blue 44, and uncut Reactant Violet X-80.

Also suitable are colorants of the formula

wherein M is an atom or group of atoms capable of bonding to the central cavity of phthalocyanine molecule, wherein axial ligands optionally can be attached to M, as disclosed in U.S. Pat. No. 6,472,523, U.S. Pat. No. 6,726,755, and U.S. Pat. No. 6,476,219, the disclosures of each of which are totally incorporated herein by reference, colorants of the formula

wherein (A) R₁ is (i) an alkylene group, (ii) an arylene group, (iii) an arylalkylene group, (iv) an alkylarylene group, (v) an alkyleneoxy group, (vi) an aryleneoxy group, (vii) an arylalkyleneoxy group, (viii) an alkylaryleneoxy group, (ix) a polyalkyleneoxy group, (x) a polyaryleneoxy group, (xi) a polyarylalkyleneoxy group, (xii) a polyalkylaryleneoxy group, (xiii) a heterocyclic group, (xiv) a silylene group, (xv) a siloxane group, (xvi) a polysilylene group, or (xvii) a polysiloxane group, (B) R₂ and R₂′ each, independently of the other, is (i) an alkyl group, (ii) an aryl group, (iii) an arylalkyl group, (iv) an alkylaryl group, (v) an alkoxy group, (vi) an aryloxy group, (vii) an arylalkyloxy group, (viii) an alkylaryloxy group, (ix) a polyalkyleneoxy group, (x) a polyaryleneoxy group, (xi) a polyarylalkyleneoxy group, (xii) a polyalkylaryleneoxy group, (xiii) a heterocyclic group, (xiv) a silyl group, (xv) a siloxane group, (xvi) a polysilylene group, (xvii) a polysiloxane group, or (xviii) a group of the formula

wherein r and s are each, independently of the other, integers representing a number of repeat —CH₂— groups, (C) R₃ and R₃′ each, independently of the other, is (i) an alkyl group, (ii) an aryl group, (iii) an arylalkyl group, or (iv) an alkylaryl group, (D) X and X′ each, independently of the other, is (i) a direct bond, (ii) an oxygen atom, (iii) a sulfur atom, (iv) a group of the formula —NR₄₀— wherein R₄₀ is a hydrogen atom, an alkyl group, an aryl group, an arylalkyl group, or an alkylaryl group, or (v) a group of the formula —CR₅₀R₆₀— wherein R₅₀ and R₆₀ each, independently of the other, is a hydrogen atom, an alkyl group, an aryl group, an arylalkyl group, or an alkylaryl group, and (E) Z and Z′ each, independently of the other, is (i) a hydrogen atom, (ii) a halogen atom, (iii) a nitro group, (iv) an alkyl group, (v) an aryl group, (vi) an arylalkyl group, (vii) an alkylaryl group, (viii) a group of the formula

wherein R₇₀ is an alkyl group, an aryl group, an arylalkyl group, an alkylaryl group, an alkoxy group, an aryloxy group, an arylalkyloxy group, an alkylaryloxy group, a polyalkyleneoxy group, a polyaryleneoxy group, a polyarylalkyleneoxy group, a polyalkylaryleneoxy group, a heterocyclic group, a silyl group, a siloxane group, a polysilylene group, or a polysiloxane group, (ix) a sulfonyl group of the formula —SO₂R₈₀ wherein R₈₀ is a hydrogen atom, an alkyl group, an aryl group, an arylalkyl group, an alkylaryl group, an alkoxy group, an aryloxy group, an arylalkyloxy group, an alkylaryloxy group, a polyalkyleneoxy group, a polyaryleneoxy group, a polyarylalkyleneoxy group, a polyalkylaryleneoxy group, a heterocyclic group, a silyl group, a siloxane group, a polysilylene group, or a polysiloxane group, or (x) a phosphoryl group of the formula —PO₃R₉₀ wherein R₉₀ is a hydrogen atom, an alkyl group, an aryl group, an arylalkyl group, an alkylaryl group, an alkoxy group, an aryloxy group, an arylalkyloxy group, an alkylaryloxy group, a polyalkyleneoxy group, a polyaryleneoxy group, a polyarylalkyleneoxy group, a polyalkylaryleneoxy group, a heterocyclic group, a silyl group, a siloxane group, a polysilylene group, or a polysiloxane group, as disclosed in U.S. Pat. No. 6,576,747, U.S. Pat. No. 6,713,614, U.S. Pat. No. 6,663,703, and U.S. Pat. No. 6,576,748, the disclosures of which are totally incorporated herein by reference, colorants of the formula

wherein Y is a hydrogen atom or a bromine atom, n is an integer of 0, 1, 2, 3, or 4, R₁ is an alkylene group or an arylalkylene group, and X is (a) a hydrogen atom, (b) a group of the formula

wherein R₂ is an alkyl group, an aryl group, an arylalkyl group, or an alkylaryl group, (c) an alkyleneoxy, aryleneoxy, arylalkyleneoxy, or alkylaryleneoxy group, or (d) a group of the formula

wherein R₄ is an alkyl group, an aryl group, an arylalkyl group, or an alkylaryl group, as disclosed in U.S. Pat. No. 6,958,406, U.S. Pat. No. 6,821,327, and Copending Application U.S. Ser. No. 10/260,379, filed Sep. 27, 2002, entitled “Methods for Making Colorant Compounds,” the disclosures of each of which are totally incorporated herein by reference, colorants of the formula

wherein M is either (1) a metal ion having a positive charge of +y wherein y is an integer which is at least 2, said metal ion being capable of forming a compound with at least two

chromogen moieties, or (2) a metal-containing moiety capable of forming a compound with at least two

chromogen moieties, z is an integer representing the number of

chromogen moieties associated with the metal and is at least 2, R₁, R₂, R₃, and R₄ each, independently of the others, is (i) a hydrogen atom, (ii) an alkyl group, (iii) an aryl group, (iv) an arylalkyl group, or (v) an alkylaryl group, wherein R₁ and P₂ can be joined together to form a ring, wherein R₃ and P₄ can be joined together to form a ring, and wherein R₁, R₂, R₃, and R₃ can each be joined to a phenyl ring in the central structure, a and b each, independently of the others, is an integer which is 0, 1, 2, or 3, c is an integer which is 0, 1, 2, 3, or 4, each R₅, R₆, and R₇, independently of the others, is (i) an alkyl group, (ii) an aryl group, (iii) an arylalkyl group, (iv) an alkylaryl group, (v) a halogen atom, (vi) an ester group, (vii) an amide group, (viii) a sulfone group, (ix) an amine group or ammonium group, (x) a nitrile group, (xi) a nitro group, (xii) a hydroxy group, (xiii) a cyano group, (xiv) a pyridine or pyridinium group, (xv) an ether group, (xvi) an aldehyde group, (xvii) a ketone group, (xviii) a carbonyl group, (xix) a thiocarbonyl group, (xx) a sulfate group, (xxi) a sulfide group, (xxii) a sulfoxide group, (xxiii) a phosphine or phosphonium group, (xxiv) a phosphate group, (xxv) a mercapto group, (xxvi) a nitroso group, (xxvii) an acyl group, (xxviii) an acid anhydride group, (xxix) an azide group, (xxx) an azo group, (xxxi) a cyanato group, (xxxii) an isocyanato group, (xxxiii) a thiocyanato group, (xxxiv) an isothiocyanato group, (xxxv) a urethane group, or (xxxvi) a urea group, wherein R₅, R₆, and R₇ can each be joined to a phenyl ring in the central structure,

R₈, R₁₀, and R₁₀ each, independently of the others, is (i) a hydrogen atom, (ii) an alkyl group, (iii) an aryl group, (iv) an arylalkyl group, or (v) an alkylaryl group, provided that the number of carbon atoms in R₁+R₂+R₃+R₄+R₅+R₆+R₇+R₈+R₉+R₁₀ is at least about 16, Q- is a COO— group or a SO₃— group, d is an integer which is 1, 2, 3, 4, or 5, A is an anion, and CA is either a hydrogen atom or a cation associated with all but one of the Q- groups, as disclosed in U.S. Pat. No. 6,835,238, Copending Application U.S. Ser. No. 10/607,373, filed Jun. 26, 2003, entitled “Colorant Compounds,” Copending Application U.S. Ser. No. 10/898,724, filed Jul. 23, 2004, entitled “Processes for Preparing Phase Change Inks,” Copending Application U.S. Ser. No. 10/898,028, entitled “Colorant Compounds,” and Copending Application U.S. Ser. No. 10/898,432, entitled “Phase Change Inks,” the disclosures of each of which are totally incorporated herein by reference, and colorants as disclosed in U.S. Pat. No. 6,472,523, U.S. Pat. No. 6,726,755, U.S. Pat. No. 6,476,219, U.S. Pat. No. 6,663,703, U.S. Pat. No. 6,755,902, U.S. Pat. No. 6,590,082, U.S. Pat. No. 6,696,552, U.S. Pat. No. 6,576,748, U.S. Pat. No. 6,646,111, and U.S. Pat. No. 6,673,139, the disclosures of each of which are totally incorporated herein by reference.

Other ink colors besides the subtractive primary colors can be desirable for applications such as postal marking, industrial marking, and labelling using phase change printing, and the inks are applicable to these needs. Further, infrared (IR) or ultraviolet (UV) absorbing dyes can also be incorporated into the inks for use in applications such as “invisible” coding or marking of products. Examples of such infrared and ultraviolet absorbing dyes are disclosed in, for example, U.S. Pat. No. 5,378,574, U.S. Pat. No. 5,146,087, U.S. Pat. No. 5,145,518, U.S. Pat. No. 5,543,177, U.S. Pat. No. 5,225,900, U.S. Pat. No. 5,301,044, U.S. Pat. No. 5,286,286, U.S. Pat. No. 5,275,647, U.S. Pat. No. 5,208,630, U.S. Pat. No. 5,202,265, U.S. Pat. No. 5,271,764, U.S. Pat. No. 5,256,193, U.S. Pat. No. 5,385,803, and U.S. Pat. No. 5,554,480, the disclosures of each of which are totally incorporated herein by reference.

In a specific embodiment, the colorant is an isocyanate-derived colored resin as disclosed in, for example, U.S. Pat. No. 5,780,528 and U.S. Pat. No. 5,919,839, the disclosures of each of which are totally incorporated herein by reference. In this embodiment, the colorant is the reaction product of a hydroxyl-substituted or primary or secondary amino-substituted chromophore with an isocyanate. Examples of suitable isocyanates include monoisocyanates, diisocyanates, triisocyanates, copolymers of a diisocyanate, copolymers of a triisocyanate, polyisocyanates (having more than three isocyanate functional groups), and the like, as well as mixtures thereof. Specific examples of suitable isocyanates include those listed hereinabove as being suitable for reaction with the hydroxyl-substituted or amino-substituted antioxidant. Examples of suitable hydroxyl-substituted and primary or secondary amino-substituted chromophores include those disclosed in, for example, U.S. Pat. No. 3,157,633, U.S. Pat. No. 3,927,044, U.S. Pat. No. 3,994,835, U.S. Pat. No. 4,102,644, U.S. Pat. No. 4,113,721, U.S. Pat. No. 4,132,840, U.S. Pat. No. 4,137,243, U.S. Pat. No. 4,170,564, U.S. Pat. No. 4,284,729, U.S. Pat. No. 4,507,407, U.S. Pat. No. 4,640,690, U.S. Pat. No. 4,732,570, U.S. Pat. No. 4,751,254, U.S. Pat. No. 4,751,254, U.S. Pat. No. 4,761,502, U.S. Pat. No. 4,775,748, U.S. Pat. No. 4,812,141, U.S. Pat. No. 4,846,846, U.S. Pat. No. 4,871,371, U.S. Pat. No. 4,912,203, U.S. Pat. No. 4,978,362, U.S. Pat. No. 5,043,013, U.S. Pat. No. 5,059,244, U.S. Pat. No. 5,149,800, U.S. Pat. No. 5,177,200, U.S. Pat. No. 5,270,363, U.S. Pat. No. 5,290,921, and 5,731,398, the disclosures of each of which are totally incorporated herein by reference. Hydroxyl-containing and primary or secondary amino-containing colorants from the classes of Color Index (C.I.) Solvent Dyes, Disperse Dyes, modified Acid and Direct Dyes, Basic Dyes, Sulphur Dyes, Vat Dyes, and the like can also be used.

The colorant is present in the phase change ink in any desired or effective amount to obtain the desired color or hue, in one embodiment at least about 0.1 percent by weight of the ink, in another embodiment at least about 0.2 percent by weight of the ink, and in yet another embodiment at least about 0.5 percent by weight of the ink, and in one embodiment no more than about 50 percent by weight of the ink, in another embodiment no more than about 20 percent by weight of the ink, and in yet another embodiment no more than about 10 percent by weight of the ink, although the amount can be outside of these ranges.

The inks can also optionally contain an antioxidant. The optional antioxidants of the ink compositions protect the images from oxidation and also protect the ink components from oxidation during the heating portion of the ink preparation process. Specific examples of suitable antioxidants include NAUGUARD® 524, NAUGUARD® 76, and NAUGUARD® 512 (commercially available from Uniroyal Chemical Company, Oxford, Conn.), IRGANOX® 1010 (commercially available from Ciba Geigy), and the like. When present, the optional antioxidant is present in the ink in any desired or effective amount, in one embodiment of at least about 0.01 percent by weight of the ink, in another embodiment of at least about 0.05 percent by weight of the ink, and in yet another embodiment of at least about 0.1 percent by weight of the ink, and in one embodiment of no more than about 20 percent by weight of the ink, in another embodiment of no more than about 5 percent by weight of the ink, and in yet another embodiment of no more than about 3 percent by weight of the ink, although the amount can be outside of these ranges.

Other optional additives to the inks include clarifiers, such as UNION CAMP® X37-523-235 (commercially available from Union Camp), in an amount in one embodiment of at least about 0.01 percent by weight of the ink, in another embodiment of at least about 0.1 percent by weight of the ink, and in yet another embodiment of at least about 5 percent by weight of the ink, and in one embodiment of no more than about 98 percent by weight of the ink, in another embodiment of no more than about 50 percent by weight of the ink, and in yet another embodiment of no more than about 10 percent by weight of the ink, although the amount can be outside of these ranges, tackifiers, such as FORAL® 85, a glycerol ester of hydrogenated abietic (rosin) acid (commercially available from Hercules), FORAL® 105, a pentaerythritol ester of hydroabietic (rosin) acid (commercially available from Hercules), CELLOLYN® 21, a hydroabietic (rosin) alcohol ester of phthalic acid (commercially available from Hercules), ARAKAWA KE-311 and KE-100 Resins, triglycerides of hydrogenated abietic (rosin) acid (commercially available from Arakawa Chemical Industries, Ltd.), synthetic polyterpene resins such as NEVTAC® 2300, NEVTAC® 100, and NEVTAC® 80 (commercially available from Neville Chemical Company), WINGTACK® 86, a modified synthetic polyterpene resin (commercially available from Goodyear), and the like, in an amount in one embodiment of at least about 0.1 percent by weight of the ink, in another embodiment of at least about 5 percent by weight of the ink, and in yet another embodiment of at least about 10 percent by weight of the ink, and in one embodiment of no more than about 98 percent by weight of the ink, in another embodiment of no more than about 75 percent by weight of the ink, and in yet another embodiment of no more than about 50 percent by weight of the ink, although the amount can be outside of these ranges, adhesives, such as VERSAMID® 757, 759, or 744 (commercially available from Henkel), in an amount in one embodiment of at least about 0.1 percent by weight of the ink, in another embodiment of at least about 1 percent by weight of the ink, and in yet another embodiment of at least about 5 percent by weight of the ink, and in one embodiment of no more than about 98 percent by weight of the ink, in another embodiment of no more than about 50 percent by weight of the ink, and in yet another embodiment of no more than about 10 percent by weight of the ink, although the amount can be outside of these ranges, plasticizers, such as UNIPLEX® 250 (commercially available from Uniplex), the phthalate ester plasticizers commercially available from Monsanto under the trade name SANTICIZER®, such as dioctyl phthalate, diundecyl phthalate, alkylbenzyl phthalate (SANTICIZER® 278), triphenyl phosphate (commercially available from Monsanto), KP-140®, a tributoxyethyl phosphate (commercially available from FMC Corporation), MORFLEX® 150, a dicyclohexyl phthalate (commercially available from Morflex Chemical Company Inc.), trioctyl trimellitate (commercially available from Eastman Kodak Co.), and the like, in an amount in one embodiment of at least about 0.1 percent by weight of the ink, in another embodiment of at least about 1 percent by weight of the ink, and in yet another embodiment of at least about 2 percent by weight of the ink, and in one embodiment of no more than about 50 percent by weight of the ink, in another embodiment of no more than about 30 percent by weight of the ink, and in yet another embodiment of no more than about 10 percent by weight of the ink, although the amount can be outside of these ranges, and the like.

The ink compositions can be prepared by any desired or suitable method. For example, the ink ingredients can be mixed together, followed by heating, to a temperature in one embodiment of at least about 100° C., and in one embodiment of no more than about 140° C., although the temperature can be outside of these ranges, and stirring until a homogeneous ink composition is obtained, followed by cooling the ink to ambient temperature (typically from about 20 to about 25° C). The inks are solid at ambient temperature. In a specific embodiment, during the formation process, the inks in their molten state are poured into molds and then allowed to cool and solidify to form ink sticks.

Specific embodiments will now be described in detail. These examples are intended to be illustrative, and the claims are not limited to the materials, conditions, or process parameters set forth in these embodiments. All parts and percentages are by weight unless otherwise indicated.

EXAMPLE I

Ink compositions were prepared by the following process. All ink ingredients except colorant(s) were charged into a stainless steel beaker. The resulting mixture was then melted together at a temperature of about 110° C. in an oven, followed by blending by stirring in a temperature controlled mantle at about 110° C. for about 0.3 hour. To this mixture was then added the colorant(s). After stirring for about 2 additional hours, the ink thus formed was filtered through a heated MOTT® apparatus (obtained from Mott Metallurgical) using Whatman #3 filter paper under a pressure of about 15 pounds per square inch. The filtered phase change ink thus formed was poured into molds and allowed to solidify to form ink sticks. Inks were prepared from the following ingredients: Polywax 500, M_(p)=572, M_(n)=516, M_(w)=570, MWD=1.10 as measured by HT-GPC (PE 500, obtained from Baker Petrolite, Tulsa, Okla.); narrow molecular weight distribution polyethylene wax (PE-C), similar to Polywax 500 but distilled to remove about 15 percent of the lower molecular weight fraction and about 15 percent of the upper molecular weight fraction, M_(p)=582, M_(n)=562, M_(w)=579, MWD=1.03 as measured by HT-GPC (obtained from Baker Petrolite, Tulsa, Okla.); Fischer-Tropsch (FT-B) wax obtained from Sasol Wax Americas, Inc. as SASOLWAX® C80, M_(p)=558, M_(n)=565, M_(w)=588, MWD=1.04 as measured by HT-GPC; Fischer-Tropsch wax (FT-C) obtained from Sasol Wax Americas, Inc., said wax being similar to SASOLWAX® C80 but having had removed by distillation the lowest 9 percent molecular weight fraction, M_(p)=620, M_(n)=619, M_(w)=635, MWD=1.03 as measured by HT-GPC; Fischer-Tropsch wax (FT-D) obtained from Sasol Wax Americas, Inc., said wax being similar to SASOLWAX® C80 but having had removed by distillation the lowest 20 percent molecular weight fraction, M_(p)=631, M_(n)=627, M_(w)=643, MWD=1.03 as measured by HT-GPC; Fischer-Tropsch wax (FT-E) obtained from Sasol Wax Americas, Inc., said wax being similar to SASOLWAX® C80 but having had removed by distillation the lowest 30 percent molecular weight fraction, M_(p)=637, M_(n)=630, M_(w)=646, MWD=1.03 as measured by HT-GPC; a branched triamide of the formula

wherein p, q, and r each have an average value of about 35, prepared as described in Example II of U.S. Pat. No. 6,860,930, the disclosure of which is totally incorporated herein by reference; stearyl stearamide wax (KEMAMIDE® S-180, obtained from Crompton Corporation, Greenwich, Conn.); KE-100 Resin (triglycerides of hydrogenated abietic (rosin) acid, obtained from Arakawa Chemical Industries (USA) Inc., Chicago, Ill.); a urethane resin that was the adduct of three equivalents of stearyl isocyanate and a glycerol-based alcohol, prepared as described in Example 4 of U.S. Pat. No. 6,309,453, the disclosure of which is totally incorporated herein by reference; NAUGUARD® 445 antioxidant (obtained from Uniroyal Chemical Co., Middlebury, Conn.); a cyan colorant as disclosed in Examples V through XI of U.S. Pat. No. 6,472,523, the disclosure of which is totally incorporated herein by reference; and dodecyl benzene sulfuric acid (DDBSA, Bio-soft S-100, obtained from Stepan Company, Elwood, Ill.). The amounts in percent by weight of the ink of each ingredient are listed in the table below for each ink:

Ink 1 2 3 4 5 6 7 PE 500 50.20 0 0 0 0 0 0 PE-C 0 50.00 51.37 0 0 0 0 FT-B 0 0 0 50 0 0 0 FT-C 0 0 0 0 55.6 0 0 FT-D 0 0 0 0 0 56.66 0 FT-E 0 0 0 0 0 0 56.66 triamide 13.90 13.95 15.34 13.95 16.81 15.5 15.5 S-180 15.14 15.14 14.75 15.14 14.56 14.7 14.7 KE-100 12.30 12.42 13.89 12.42 8.4 8.5 8.5 urethane wax 4.42 4.42 0.93 4.42 0.9 0.91 0.91 DDBSA 0.32 0.35 0 0.35 0 0 0 N-445 0.17 0.17 0.17 0.17 0.17 0.17 0.17 cyan colorant 3.55 3.55 3.55 3.55 3.56 3.56 3.56 Ink 1 is provided for comparative purposes.

Ink Characteristics

Various characteristics of the inks were measured by a Rheometrics cone-plate viscometer and are indicated in the table below. Viscosity (η, centipoise) was measured at 110° C. The spectral strength was determined using a spectrophotographic procedure based on the measurement of the ink in solution by dissolving the ink in toluene for the cyan and yellow inks and n-butanol for the magenta inks and measuring the absorbance using a Perkin Elmer Lambda 2S UV/VIS spectrophotometer. Glass transition temperature (T_(g)) was measured by Dynamic Mechanic Analysis using a Rheometrics Solid Analyzer (RSA II). Peak melting point (MP) and peak freezing point (FP) were measured by differential scanning calorimetry (DSC) using a DUPONT 2100 calorimeter.

Ink 1 2 3 4 5 6 7 η 10.72 10.63 10.73 11.03 10.75 10.62 10.69 SS 4510 4503 4538 4517 4547 4582 4596 T_(g) 11.51 12.88 28.45, −16.83 9.31, −17.97 −16.5, 5.9 −17.8, 12.5 −16.6, −11.5 MP 81.92 80.81 80.99 81.85 83.03 83.58 83.99 FP 69.6, 74.5 69.19 71.95 69.1 73.3, 76.4 73.8, 76.9 73.9, 77.6 As the data indicate, the peak melting points of these inks are about 80° C. and the viscosities of most of them are close to about 10.6 at 110° C., indicating that they are suitable for jetting at temperatures of from about 105 to about 115° C. The spectral strengths confirm good dissolution of the cyan colorants. In addition, the inks prepared from the polyethylene waxes having about 15 percent of the lower molecular weight fraction and about 15 percent of the upper molecular weight fraction removed therefrom and ink 4 prepared from Fischer-Tropsch wax C80 exhibited desirably low freezing points, enabling setting printer standby temperatures at lower settings and thus enabling low energy consumption. The reduced freezing point of these inks is believed to be attributable to the removal of the upper molecular weight fraction of the polyethylene wax. The cohesive failure temperature, intermediate transfer setpoint temperature, minimum jetting temperature, and minimum standby temperature for inks 1 and 2 in a XEROX® PHASER® 8400 printer were as indicated in the table below. For comparative purposes, these characteristics were also measured for the commercial cyan inks supplied for a XEROX® PHASER® 8400 printer and for a XEROX® PHASER® 360 printer, and are also indicated in the table below.

Intermediate Cohesive Transfer Minimum Minimum Failure Temp. Member Jetting Temp. Standby Ink (° C.) Temp. (° C.) (° C.) Temp. (° C.) 8400 73 62-64 130 105 360 63 50-57 130 105 1 55 45 110  92-95 2 65 60 110  88-90 4 65 54 114 — 5 72 60-62 115 — 6 72 60-62 114 — 7 72 60-62 115 — — = not measured As the data indicate, Inks 2, 4, 5, 6, and 7 exhibit both a desirably high cohesive failure temperature of at least about 56° C. or higher and a desirably low jetting temperature of about 125° C. or lower. Ink 2 also exhibits a desirably low minimum standby temperature. While the minimum standby temperature was not measured for inks 4, 5, 6, and 7, it is believed that these inks will also have desirably low minimum standby temperatures.

Standby Temperatures

Inks 1 and 2 as well as the commercial cyan ink supplied for a XEROX® PHASER® 8400 printer were evaluated for minimum standby temperature. The inks were each incorporated into a XEROX® PHASER® 8400 printer, after which the printer was placed in power saver mode for periods of overnight and over a weekend. Thereafter, prints were generated and the percentage of failed jets was determined from the prints thus generated at various power saver temperatures. The results were as follows:

% Failed Jets After Recovery from Given Power Saver Temp. Standby 8400 ink Ink 1 Ink 2 Ink 1 Ink 2 temp. (° C.) (overnight) (overnight) (overnight) (weekend) (weekend) 85 100 >6 28 >9 28 87 100 >6 3 >9 6 88 100 >6 0 >9 0 90 100 6 0 9 0 92 100 0 0 2 0 95 100 0 0 0 0 100 36 0 0 0 0 104 1 0 0 0 0 105 0 0 0 0 0 110 0 0 0 0 0 115 0 0 0 0 0 From this data, one can conclude that the minimum standby temperature for the 8400 ink is about 104° C., for Ink 1 is about 92° C., and for Ink 2 is about 88° C.

Other embodiments and modifications of the present invention may occur to those of ordinary skill in the art subsequent to a review of the information presented herein; these embodiments and modifications, as well as equivalents thereof, are also included within the scope of this invention.

The recited order of processing elements or sequences, or the use of numbers, letters, or other designations therefor, is not intended to limit a claimed process to any order except as specified in the claim itself. 

1. A phase change ink composition comprising an ink carrier and a colorant, said ink being suitable for use in an indirect printing process wherein the ink is jetted from a printhead onto a heated intermediate transfer member and subsequently transferred from the intermediate transfer member to a final recording substrate, wherein: (a) the ink exhibits the characteristic of being jetted from the printhead onto the intermediate transfer member when the ink is at a temperature of about 125° C. or lower; (b) the ink exhibits the characteristic of being jetted without purging from a printer maintained at a standby temperature of about 100° C. or lower; and (c) the ink has a cohesive failure temperature of at least about 56° C.
 2. An ink according to claim 1 wherein the ink exhibits the characteristic of being jetted from the printhead onto the intermediate transfer member when the ink is at a temperature of about 120° C. or lower.
 3. An ink according to claim 1 wherein the ink exhibits the characteristic of being jetted from the printhead onto the intermediate transfer member when the ink is at a temperature of about 115° C. or lower.
 4. An ink according to claim 1 wherein the ink exhibits the characteristic of being jetted from the printhead onto the intermediate transfer member when the ink is at a temperature of about 113° C. or lower.
 5. An ink according to claim 1 wherein the ink exhibits the characteristic of being jetted without purging from a printer maintained at a standby temperature of about 95° C. or lower.
 6. An ink according to claim 1 wherein the ink exhibits the characteristic of being jetted without purging from a printer maintained at a standby temperature of about 90° C. or lower.
 7. An ink according to claim 1 wherein the ink has a cohesive failure temperature of at least about 60° C.
 8. An ink according to claim 1 wherein the ink has a cohesive failure temperature of at least about 65° C.
 9. An ink according to claim 1 wherein the ink has a peak melting point of no higher than about 160° C.
 10. An ink according to claim 1 wherein the ink has a peak melting point of no higher than about 140° C.
 11. An ink according to claim 1 wherein the ink has a peak melting point of no higher than about 100° C.
 12. An ink according to claim 1 wherein the ink has an onset melting point of no lower than about 50° C.
 13. An ink according to claim 1 wherein the ink has an onset melting point of no lower than about 52° C.
 14. An ink according to claim 1 wherein the ink has an onset melting point of no lower than about 55° C.
 15. An ink according to claim 1 wherein the ink has a melt viscosity at the jetting temperature of no more than about 30 centipoise.
 16. An ink according to claim 1 wherein the ink has a melt viscosity at the jetting temperature of no more than about 20 centipoise.
 17. An ink according to claim 1 wherein the ink has a melt viscosity at the jetting temperature of no more than about 15 centipoise.
 18. An ink according to claim 1 wherein the ink has a viscosity of from about 7 to about 15 centipoise at a temperature of about 110° C.
 19. An ink according to claim 1 wherein the ink has a viscosity of from about 7 to about 15 centipoise at a temperature of about 115° C.
 20. An ink according to claim 1 wherein the ink has a viscosity of from about 7 to about 15 centipoise at a temperature of about 120° C.
 21. An ink according to claim 1 wherein the ink carrier comprises (i) a branched triamide and (ii) a polyethylene wax.
 22. An ink according to claim 1 wherein the ink carrier comprises (i) a branched triamide and (ii) a Fischer-Tropsch wax.
 23. An ink according to claim 1 wherein the ink meets requirements (a) and (b) with no more than about 2 percent failed jets.
 24. An ink according to claim 1 wherein the ink meets requirements (a) and (b) with no more than about 1 percent failed jets.
 25. An ink according to claim 1 wherein the ink meets requirements (a) and (b) with no more than about 0.5 percent failed jets.
 26. An ink according to claim 1 wherein the ink meets requirements (a) and (b) with no more than about 0.25 percent failed jets.
 27. A phase change ink composition comprising an ink carrier and a colorant, said ink being suitable for use in an indirect printing process wherein the ink is jetted from a printhead onto a heated intermediate transfer member and subsequently transferred from the intermediate transfer member to a final recording substrate, wherein: (a) the ink exhibits the characteristic of being jetted from the printhead onto the intermediate transfer member when the ink is at a temperature of about 120° C. or lower; (b) the ink exhibits the characteristic of being jetted without purging from a printer maintained at a standby temperature of about 95° C. or lower; and (c) the ink has a cohesive failure temperature of at least about 60° C.
 28. A phase change ink composition comprising an ink carrier and a colorant, said ink being suitable for use in an indirect printing process wherein the ink is jetted from a printhead onto a heated intermediate transfer member and subsequently transferred from the intermediate transfer member to a final recording substrate, wherein: (a) the ink exhibits the characteristic of being jetted from the printhead onto the intermediate transfer member when the ink is at a temperature of about 115° C. or lower; (b) the ink exhibits the characteristic of being jetted without purging from a printer maintained at a standby temperature of about 90° C. or lower; and (c) the ink has a cohesive failure temperature of at least about 65° C. 